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Articles 991 - 1020 of 1348

Full-Text Articles in Physical Sciences and Mathematics

Automatic Annotation Of Referring Expression In Situated Dialogues, Niels Schütte, John D. Kelleher, Brian Mac Namee Jan 2011

Automatic Annotation Of Referring Expression In Situated Dialogues, Niels Schütte, John D. Kelleher, Brian Mac Namee

Articles

To apply machine learning techniques to the production and interpretation of natural language, we need large amounts of annotated language data. Manual annotation, however, is an expensive and time consuming process since it involves human annotators looking at the data and explicitly adding information that is implicitly contained in the data, based on their judgment. This work presents an approach to automatically annotating referring expressions in situated dialogues by exploiting the interpretation of language by the participants in the dia- logue. We associate instructions concerning objects in the environment with automatically detected events involving these objects and predict the referents …


Daemon Decay And Cosmic Inflation, Emil Prodanov Jan 2011

Daemon Decay And Cosmic Inflation, Emil Prodanov

Articles

Quantum tunneling in Reissner--Nordstroem geometry is studied and the tunneling rate is determined. A possible scenario for cosmic inflation, followed by reheating phases and subsequent radiation-domination expansion, is proposed.


On The Singular Weyl-Titchmarsh Function Of Perturbed Spherical Schrödinger Operators, Aleksey Kostenko, Gerald Teschl Jan 2011

On The Singular Weyl-Titchmarsh Function Of Perturbed Spherical Schrödinger Operators, Aleksey Kostenko, Gerald Teschl

Articles

We investigate the singular Weyl–Titchmarsh m-function of perturbed spherical Schrödinger operators (also known as Bessel operators) under the assumption that the perturbation q(x) satisfies xq(x) ∈ L1(0, 1). We show existence plus detailed properties of a fundamental system of solutions which are entire with respect to the energy parameter. Based on this we show that the singular mfunction belongs to the generalized Nevanlinna class and connect our results with the theory of super singular perturbations.


On The (Non)-Integrability Of Kdv Hierarchy With Self-Consistent Sources, Vladimir Gerdjikov, Georgi Grahovski, Rossen Ivanov Jan 2011

On The (Non)-Integrability Of Kdv Hierarchy With Self-Consistent Sources, Vladimir Gerdjikov, Georgi Grahovski, Rossen Ivanov

Articles

Nonholonomic deformations of integrable equations of the KdV hierarchy are studied by using the expansions over the so-called “squared solutions” (squared eigenfunctions). Such deformations are equivalent to a perturbed model with external (self-consistent) sources. In this regard, the KdV6 equation is viewed as a special perturbation of KdV. Applying expansions over the symplectic basis of squared eigenfunctions, the integrability properties of the KdV6 equation are analysed. This allows for a formulation of conditions on the perturbation terms that preserve its integrability. The perturbation corrections to the scattering data and to the corresponding action-angle (canonical) variables are studied. The analysis shows …


Rational Bundles And Recursion Operators For Integrable Equations On A.Iii-Type Symmetric Spaces, Vladimir Gerdjikov, Georgi Grahovski, Alexander Mikhailov, Tihomir Valtchev Jan 2011

Rational Bundles And Recursion Operators For Integrable Equations On A.Iii-Type Symmetric Spaces, Vladimir Gerdjikov, Georgi Grahovski, Alexander Mikhailov, Tihomir Valtchev

Articles

We analyze and compare the methods of construction of the recursion operators for a special class of integrable nonlinear differential equations related to A.III-type symmetric spaces in Cartan’s classification and having additional reductions.


Polynomial Bundles And Generalised Fourier Transforms For Integrable Equations On A.Iii-Type Symmetric Spaces, Vladimir Gerdjikov, Georgi Grahovski, Alexander V. Mikhailov, Tihomir Valchev Jan 2011

Polynomial Bundles And Generalised Fourier Transforms For Integrable Equations On A.Iii-Type Symmetric Spaces, Vladimir Gerdjikov, Georgi Grahovski, Alexander V. Mikhailov, Tihomir Valchev

Articles

A certain class of integrable nonlinear differential equations related to A.III-type symmetric spaces and having additional reductions is analysed via the Inverse Scattering Method (ISM). The class contains systems of nonlinear evolution equations (NLEEs) associated with a Lax operator (for the time-evolution) polynomial in the spectral parameter. Using the Wronskian relations, the mapping between the potential and the minimal sets of scattering data is constructed. Furthermore, completeness relations for the `squared solutions' (generalised exponentials) are derived. Next, expansions of Q and its variation are obtained. This demonstrates that the interpretation of the inverse scattering method as a generalized Fourier transform …


Holomorphic Liftings From Infinite Dimensional Spaces, Sean Dineen, Milena Venkova Jan 2011

Holomorphic Liftings From Infinite Dimensional Spaces, Sean Dineen, Milena Venkova

Articles

We obtain a number of positive solutions to a holomorphic lifting problem on a domain in a locally convex space.


On Socle-Regularity And Some Notions Of Transitivity For Abelian P-Groups, Brendan Goldsmith, Peter Danchev Jan 2011

On Socle-Regularity And Some Notions Of Transitivity For Abelian P-Groups, Brendan Goldsmith, Peter Danchev

Articles

In the present work the interconnections between various notions of transitivity for Abelian p-groups and the recently introduced concepts of socle-regular and strongly socle-regular groups are studied.


Bayesian Inference For Exponential Random Graph Models, Alberto Caimo, Nial Friel Jan 2011

Bayesian Inference For Exponential Random Graph Models, Alberto Caimo, Nial Friel

Articles

Exponential random graph models are extremely difficult models to handle from a statistical viewpoint, since their normalising constant, which depends on model parameters, is available only in very trivial cases. We show how inference can be carried out in a Bayesian framework using a MCMC algorithm, which circumvents the need to calculate the normalising constants. We use a population MCMC approach which accelerates convergence and improves mixing of the Markov chain. This approach improves performance with respect to the Monte Carlo maximum likelihood method of Geyer and Thompson (1992).


Now For The Science Bit: Implementing Community-Based Learning In Chemistry, Claire M. Mcdonnell, Patricia Ennis, Leslie Shoemaker Jan 2011

Now For The Science Bit: Implementing Community-Based Learning In Chemistry, Claire M. Mcdonnell, Patricia Ennis, Leslie Shoemaker

Articles

Purpose – The purpose of this paper is to contribute to the understanding of student learning from community engagement by critically assessing the implementation of this pedagogical approach in the context of teaching and learning chemistry and also evaluating the role of personal development in student-community engagement.

Design/methodology/approach – A case study on the implementation since 2007 of community-based learning (also called service-learning) projects in an academic department in Ireland is presented. Analysis of assessment grades, student reflective accounts and evaluation questionnaires informs this work as does a recently completed self-assessment of our activities using Shumer’s Self-Assessment for Service Learning. …


Di-Tert Butyl Chlorosilane, Gráinne Hargaden, Timothy O'Sullivan Jan 2011

Di-Tert Butyl Chlorosilane, Gráinne Hargaden, Timothy O'Sullivan

Articles

No abstract provided.


In-Plane Sensitive Electronic Speckle Pattern Interferometer Using A Diffractive Holographic Optical Element, Raghavendra Jallapuram, Con Healy, Emilia Mihaylova, Vincent Toal Jan 2011

In-Plane Sensitive Electronic Speckle Pattern Interferometer Using A Diffractive Holographic Optical Element, Raghavendra Jallapuram, Con Healy, Emilia Mihaylova, Vincent Toal

Articles

We describe a student project in electronic speckle pattern interferometry. The project includes holographic recording of diffraction gratings in thick, self-processing photopolymer layers made from off-the-shelf chemicals. The gratings are employed in a simple electronic speckle pattern interferometer to measure in-plane rotation.


Comparative Imaging Study In Ultrasound, Mri, Ct And Dsa Using A Multi-Modality Renal Artery Phantom, Deirdre King, Andrew Fagan, Carmel Moran, Jacinta Browne Jan 2011

Comparative Imaging Study In Ultrasound, Mri, Ct And Dsa Using A Multi-Modality Renal Artery Phantom, Deirdre King, Andrew Fagan, Carmel Moran, Jacinta Browne

Articles

A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease.

Methods:

The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use …


Currency Trading Using The Fractal Market Hypothesis, Jonathan Blackledge, Kieran Murphy Jan 2011

Currency Trading Using The Fractal Market Hypothesis, Jonathan Blackledge, Kieran Murphy

Articles

We report on a research and development programme in financial modelling and economic security undertaken in the Information and Communications Security Research Group (ICSRG, 2011) which has led to the launch of a new company - Currency Traders Ireland Limited - funded by Enterprise Ireland. Currency Traders Ireland Limited (CTI, 2011) has a fifty year exclusive license to develop a new set of indicators for analysing currency exchange rates (Forex trading). We consider the background to the approach taken and present examples of the results obtained to date.


A Generalized Nonlinear Model For The Evolution Of Low Frequency Freak Waves, Jonathan Blackledge Jan 2011

A Generalized Nonlinear Model For The Evolution Of Low Frequency Freak Waves, Jonathan Blackledge

Articles

This paper presents a generalized model for simulating wave fields associated with the sea surface. This includes the case when `freak waves' may occur through an effect compounded in the nonlinear (cubic) Schrodinger equation. After providing brief introductions to linear sea wave models, `freak waves' and the linear and nonlinear Schrodinger equations, we present a unified model that provides for a piecewise continuous transition from a linear to a nonlinear state. This is based on introducing a fractional time derivative to develop a fractional nonlinear partial differential equation with a stochastic source function. In order to explore the characteristics of …


Water-Soluble Cuii And Mnii Bis-Phenanthroline Octanedioate Complexes With Unprecedented Nano And Picomolar In Vitro Cytotoxicity As Promising Leads For Chemotherapeutic Drug Development, Andrew Kellett, Mark O'Connor, Malachy Mccann, Orla L. Howe, Alan Casey, Pauric Mccarron, Kevin Kavanagh, Mary Mcnamara, Sean Kennedy, Donald D. May, Philip S. Skell, Denis O'Shea, Michael Devereux Jan 2011

Water-Soluble Cuii And Mnii Bis-Phenanthroline Octanedioate Complexes With Unprecedented Nano And Picomolar In Vitro Cytotoxicity As Promising Leads For Chemotherapeutic Drug Development, Andrew Kellett, Mark O'Connor, Malachy Mccann, Orla L. Howe, Alan Casey, Pauric Mccarron, Kevin Kavanagh, Mary Mcnamara, Sean Kennedy, Donald D. May, Philip S. Skell, Denis O'Shea, Michael Devereux

Articles

Dinuclear CuII and MnII bis-phenanthroline octanedioate complexes exhibit rapid, unprecedented nano and picomolar in vitro cytotoxicity against colorectal cancer lines and are less toxic than cisplatin when examined in vivo. The complexes are potent generators of cellular reactive oxygen species, avid DNA binders and induce O2 dependent cleavage of DNA. The Cu(II) complex was found to have self-cleaving nuclease activity.


Comparative Imaging Study In Ultrasound Mri, Ct And Dsa Using A Multi-Modality Renal Artery Phantom, Deirdre King, Andrew Fagan, Carmel Moran, Jacinta Browne Jan 2011

Comparative Imaging Study In Ultrasound Mri, Ct And Dsa Using A Multi-Modality Renal Artery Phantom, Deirdre King, Andrew Fagan, Carmel Moran, Jacinta Browne

Articles

A range of anatomically-realistic multi-modality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS is currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease.

Methods: The phantoms, which contained a range of stenosis values (0, 30, 50, 70 and 85%), were designed for use with …


Increased Tolerance To Abiotic Stresses In Tobacco Plants Expressing A Barley Cell Wall Peroxidase, Philippe Pringuet, Norman Mcmillan, Greg Doyle, Stephen Smith, Sebastian Riedel Jan 2011

Increased Tolerance To Abiotic Stresses In Tobacco Plants Expressing A Barley Cell Wall Peroxidase, Philippe Pringuet, Norman Mcmillan, Greg Doyle, Stephen Smith, Sebastian Riedel

Articles

Tensiography is a technique that determines the physical and chemical properties of a liquid by illuminating a growing pendant drop from within using a source fibre. Light reflected internally at the surface of the drop is recieved by a collector fibre and is converted into an electric signal called a tensiotrace, which is a graph of reflected light as a function of drop volume. The instrument obtaining this signal is called multianalyser. A numerical model that simulates tensiotraces through a raytracing analysis (RAST - Raytracing Analysis for the Simulation of Tensiotraces) of the multianalyser as been developed to define theoretically …


Non Aggregated Colloidal Silver Nanoparticles For Surface Enhanced Resonance Raman Spectroscopy, Aoife Power, John Cassidy, Tony Betts Jan 2011

Non Aggregated Colloidal Silver Nanoparticles For Surface Enhanced Resonance Raman Spectroscopy, Aoife Power, John Cassidy, Tony Betts

Articles

Silver nanoparticles with a tuneable l max were produced as colloids by heterogeneous nucleation. The synthesis process is both fast and repeatable, producing stable PVA capped nanoparticles. The colloid’s effectiveness in the SERRS system was investigated using Rhodamine 6G, R6G, Crystal Violet, CV, and Malachite Green, MG, as probe molecules. A clear sensing trend was observed, where the Raman signal emitted was significantly enhanced by the addition of silver nanoparticles. A build up of signal intensity is observed until an optimum ratio is achieved, followed by a decline in signal intensity as the concentration of nanoparticles is further increased. The …


Chromium Salen, Gráinne Hargaden, Pier Giorgio Cozzi Jan 2011

Chromium Salen, Gráinne Hargaden, Pier Giorgio Cozzi

Articles

No abstract provided.


A Practical Photoelectrochemical Cell Using Nonprecious Metal Electrodes, Patrick Enright, Tony Betts, John Cassidy Jan 2011

A Practical Photoelectrochemical Cell Using Nonprecious Metal Electrodes, Patrick Enright, Tony Betts, John Cassidy

Articles

Abstract: Photoelectrochemical cells (PECs) can be used to harvest light from the oxidation of dissolved organic matter. Similar to fuel cells but requiring light to operate, PECs contain a light assisted electrode that oxidises electron rich materials (anode); these electrons then flow to a typically Pt cathode where O2 is normally the electron acceptor. In this work a PEC cell containing inexpensive materials was shown to (a) mineralise typical organic compounds present in waste water and (b) produce electricity from their decomposition. The PEC cell consisted of a TiO2 coated conducting ink anode exposed to a light source, …


Development Of A Vessel Mimicking Material For Use In Anatomically Realistic Doppler Flow Phantoms, Deirdre King, Carmel Moran, John Mcnamara, Andrew Fagan, Jacinta Browne Jan 2011

Development Of A Vessel Mimicking Material For Use In Anatomically Realistic Doppler Flow Phantoms, Deirdre King, Carmel Moran, John Mcnamara, Andrew Fagan, Jacinta Browne

Articles

Polyvinyl alcohol cryogel, (PVA-C) is presented as a vessel mimicking material for use in anatomically realistic Doppler flow phantoms. Three different batches of 10 % wt PVA-C containing (i) PVA-C alone, (ii) PVA-C with anti-bacterial agent and (iii) PVA-C with silicon carbide particles were produced, each with 1 to 6 freeze-thaw cycles. The resulting PVA-C samples were characterized acoustically (over a range 2.65 - 10.5 MHz) and mechanically in order to determine the optimum mixture and preparation for mimicking the properties of healthy and diseased arteries found in vivo. This optimum mix was reached with the PVA-C with anti-bacterial agent …


Comment On C.E. Close, M.R. Gleeson And J.T. Sheridan "Monomer Diffusion Rates In Photopolymer Material Part 1. Low Spatial Frequency Holographic Gratings, Vincent Toal, Suzanne Martin, Izabela Naydenova Jan 2011

Comment On C.E. Close, M.R. Gleeson And J.T. Sheridan "Monomer Diffusion Rates In Photopolymer Material Part 1. Low Spatial Frequency Holographic Gratings, Vincent Toal, Suzanne Martin, Izabela Naydenova

Articles

COMMENT: on C. E. Close, M. R. Gleeson and J. T. Sheridan “Monomer diffusion rates in photopolymer material.Part I. Low spatial frequency holographic gratings” J. Opt. Soc. Am. B / Vol. 28, No. 4 / April 2011 pp 658- 666 [1]


Estimating The Efficacy Of Mild Heating Processes Taking Into Account Microbial Non-Linearities: A Case Study On The Thermisation Of A Food Simulant, Vasilis Valdramidis, Brijesh Tiwari, Patrick J. Cullen, Alain Kondjoyan, Jan Van Impe Jan 2011

Estimating The Efficacy Of Mild Heating Processes Taking Into Account Microbial Non-Linearities: A Case Study On The Thermisation Of A Food Simulant, Vasilis Valdramidis, Brijesh Tiwari, Patrick J. Cullen, Alain Kondjoyan, Jan Van Impe

Articles

Traditional and novel approaches for the calculation of the heat treatment efficiency are compared in this work. The Mild Heat value (MH-value), an alternative approach to the commonly used sterilisation, pasteurisation and cook value (F, P, C–value), is calculated to estimate the efficiency of a mild heat process. MH-value is the time needed to achieve a predefined microbial reduction at a reference temperature and a known thermal resistant constant, z, for log-linear or specific types of non log-linear microbial inactivation kinetics. An illustrative example is given in which microbial inactivation data of Listeria innocua CLIP 20-595 are used for estimating …


Water-Soluble Bis(1,10-Phenanthroline) Octanedioate Cu2+ And Mn2+ Complexes With Unprecedented Nano And Picomolar In Vitro Cytotoxicity: Promising Leads For Chemotherapeutic Drug Development, Andrew Kellett, Mark O'Connor, Malachy Mccann, Orla Howe, Alan Casey, Pauraic Mccarron, Kevin Kavanagh, Mary Mcnamara, Sean Kennedy, Donald May, Philip Skell, Denis O'Shea, Michael Devereux Jan 2011

Water-Soluble Bis(1,10-Phenanthroline) Octanedioate Cu2+ And Mn2+ Complexes With Unprecedented Nano And Picomolar In Vitro Cytotoxicity: Promising Leads For Chemotherapeutic Drug Development, Andrew Kellett, Mark O'Connor, Malachy Mccann, Orla Howe, Alan Casey, Pauraic Mccarron, Kevin Kavanagh, Mary Mcnamara, Sean Kennedy, Donald May, Philip Skell, Denis O'Shea, Michael Devereux

Articles

Dinuclear CuII and MnII bis-phenanthroline octanedioate complexes exhibit rapid, unprecedented nano and picomolar in vitro cytotoxicity against colorectal cancer lines and are less toxic than cisplatin when examined in vivo. The complexes are potent generators of cellular reactive oxygen species, avid DNA binders and induce O2 dependent cleavage of DNA. The Cu(II) complex was found to have self-cleaving nuclease activity.


Mobile Visibility Querying For Lbs, James Carswell, Keith Gardiner, Junjun Jin Dec 2010

Mobile Visibility Querying For Lbs, James Carswell, Keith Gardiner, Junjun Jin

Articles

This article describes research carried out in the area of mobile spatial interaction (MSI) and the development of a 3D mobile version of a 2D web-based directional query processor. The TellMe application integrates location (from GPS, GSM, WiFi) and orientation (from magnetometer/accelerometer) sensor technologies into an enhanced spatial query processing module capable of exploiting a mobile device’s position and orientation for querying real-world spatial datasets. This article outlines our technique for combining these technologies and the architecture needed to deploy them on a sensor enabled smartphone (i.e. Nokia Navigator 6210). With all these sensor technologies now available on off-the-shelf devices, …


Development And Validation Of A Rapid Multi-Class Method For The Confirmation Of Fourteen Prohibited Medicinal Additives In Pig And Poultry Compound Feed By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Marella Gallagher, Sean Earley, Paula Shearan, Edward Malone Dec 2010

Development And Validation Of A Rapid Multi-Class Method For The Confirmation Of Fourteen Prohibited Medicinal Additives In Pig And Poultry Compound Feed By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Marella Gallagher, Sean Earley, Paula Shearan, Edward Malone

Articles

A confirmatory method has been developed to allow for the analysis of fourteen prohibited medicinal additives in pig and poultry compound feed. These compounds are prohibited for use as feed additives although some are still authorised for use in medicated feed. Feed samples are extracted by acetonitrile with addition of sodium sulphate. The extracts undergo a hexane wash to aid with sample purification. The extracts are then evaporated to dryness and reconstituted in initial mobile phase. The samples undergo an ultracentrifugation step prior to injection onto the LC-MS/MS system and are analysed in a run time of 26 minutes. The …


Hexakis(Prop-2-Enamide)Copper(Ii) Bis(Perchlorate) And Hexakis(Prop-2- Enamide)Manganese(Ii) Bis(Perchlorate), Mary Mcnamara, Andrew Kellett, Georgina Rosair, Michael Devereux, Malachy Mccann Nov 2010

Hexakis(Prop-2-Enamide)Copper(Ii) Bis(Perchlorate) And Hexakis(Prop-2- Enamide)Manganese(Ii) Bis(Perchlorate), Mary Mcnamara, Andrew Kellett, Georgina Rosair, Michael Devereux, Malachy Mccann

Articles

The structures of [Cu(AA)6](ClO4)2, (I), and [Mn(AA)6](ClO4)2, (II) (AA is acrylamide, also known as prop-2-enamide; C3H5NO), display both intra- and intermolecular N-H...O hydrogen bonding. A three-dimensional network is propagated via the perchlorate counter-ions. There are two crystallographically independent molecules in the copper complex, with the most significant difference between them being the conformation of one symmetry-related pair of AA ligands which are in the unusual syn conformation. The copper complex exhibits syn/anti disorder of the =CH2 group in one pair of symmetry-related AA ligands. The CuII and MnII centres are both situated on centres of inversion. The copper complex cation …


Extended Green-Liouville Asymptotics And Vacuum Polarization For Lukewarm Black Holes, Cormac Breen, Adrian Ottewill Oct 2010

Extended Green-Liouville Asymptotics And Vacuum Polarization For Lukewarm Black Holes, Cormac Breen, Adrian Ottewill

Articles

We consider a quantum field on a lukewarm black hole spacetime. We introduce a new uniform approximation to the radial equation, constructed using an extension of Green-Liouville asymptotics. We then use this new approximation to construct the renormalized vacuum polarization in the Hartle-Hawking vacuum. Previous calculations of the vacuum polarization rely on the WKB approximation to the solutions of the radial equation, however the nonuniformity of the WKB approximations obscures the results of these calculations near both horizons. The use of our new approximation eliminates these obscurities, enabling us to obtain explicitly finite and easily calculable values of the vacuum …


Application Of The Fractional Diffusion Equation For Predicting Market Behaviour, Jonathan Blackledge Oct 2010

Application Of The Fractional Diffusion Equation For Predicting Market Behaviour, Jonathan Blackledge

Articles

Most Financial modelling system rely on an underlying hypothesis known as the Eficient Market Hypothesi (EMH) including the famous BlackScholes formula for placing an option. However, the EMH has a fundamental flaw: it is based on the assumption that economic processes are normally distributed and it has long been known that this is not the case. This fundamental assumption leads to a number of shortcomings associated with using the EMH to analyse financial data which includes failure to predict the future volatility of a market share value. This paper introduces a new financial risk assessment model based on Levy statistics …