Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Technological University Dublin

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1771 - 1800 of 2383

Full-Text Articles in Physical Sciences and Mathematics

Applying Geographic Information Systems To Support Strategic Environmental Assessment: Opportunities And Limitations In The Context Of Irish Land-Use Plans, Ainhoa Gonzalez, Alan Gilmer, Ronan Foley, John Sweeney, John Fry Jan 2010

Applying Geographic Information Systems To Support Strategic Environmental Assessment: Opportunities And Limitations In The Context Of Irish Land-Use Plans, Ainhoa Gonzalez, Alan Gilmer, Ronan Foley, John Sweeney, John Fry

Articles

The strengthening of spatial database infrastructures, further promoted by the INSPIRE Directive adopted in 2007, has led to an increased use of spatial data in planning and decision-making. Given that land-use plans are intrinsically spatial, such evidence and approaches can significantly benefit plan-making. A spatial framework could especially support the specific Strategic Environmental Assessment (SEA) aspects of the plan-making process. Spatial tools such as Geographic Information Systems (GIS) are particularly well-placed to support the environmental integration sought in SEA by providing evidence through the spatial assessment of multiple environmental datasets. Moreover, GIS bring the opportunity to augment conventional assessment techniques …

Go to article

Clustering Weblogs On The Basis Of A Topic Detection Method, Fernando Perez-Tellez, David Pinto, John Cardiff, Paolo Rosso Jan 2010

Clustering Weblogs On The Basis Of A Topic Detection Method, Fernando Perez-Tellez, David Pinto, John Cardiff, Paolo Rosso

Conference Papers

In recent years we have seen a vast increase in the volume of information published on weblog sites and also the creation of new web technologies where people discuss actual events. The need for automatic tools to organize this massive amount of information is clear, but the particular characteristics of weblogs such as shortness and overlapping vocabulary make this task difficult. In this work, we present a novel methodology to cluster weblog posts according to the topics discussed therein. This methodology is based on a generative probabilistic model in conjunction with a Self-Term Expansion methodology. We present our results which …

Go to article

Evaluation Of The Potential Of Raman Microspectroscopy For Prediction Of Chemotherapeutic Response To Cisplatin In Lung Adenocarcinoma, Haq Nawaz, Franck Bonnier, Peter Knief, Orla Howe, Fiona Lyng, Aidan Meade, Hugh Byrne Jan 2010

Evaluation Of The Potential Of Raman Microspectroscopy For Prediction Of Chemotherapeutic Response To Cisplatin In Lung Adenocarcinoma, Haq Nawaz, Franck Bonnier, Peter Knief, Orla Howe, Fiona Lyng, Aidan Meade, Hugh Byrne

Articles

The study of the interaction of anticancer drugs with mammalian cells in vitro is important to elucidate the mechanisms of action of the drug on its biological targets. In this context, Raman spectroscopy is a potential candidate for high throughput, noninvasive analysis. To explore this potential, the interaction of cis-Diamminedichloroplatinum (II) (Cisplatin) with a human lung adenocarcinoma cell line (A549) was investigated using Raman microspectroscopy. The results were correlated with parallel measurements from the MTT cytotoxicity assay, which yielded an IC50 value of 1.2±0.2 μM. To further confirm the spectral results, Raman spectra were also acquired from DNA extracted from …

Go to article

Investigation Of The Influence Of High Risk Human Papillomavirus On The Biochemical Composition Of Cervical Cancer Cells Using Vibrational Spectroscopy, Kamila Ostrowska, Alison Malkin, Aidan Meade, John O'Leary, Cara Martin, Cathy Spillane, Hugh Byrne, Fiona Lyng Jan 2010

Investigation Of The Influence Of High Risk Human Papillomavirus On The Biochemical Composition Of Cervical Cancer Cells Using Vibrational Spectroscopy, Kamila Ostrowska, Alison Malkin, Aidan Meade, John O'Leary, Cara Martin, Cathy Spillane, Hugh Byrne, Fiona Lyng

Articles

The main aetiology of cervical cancer is infection with high risk human papillomavirus (HPV). Cervical cancer is almost 100% curable if detected in the early stages. Thus, information about the presence and levels of HPV in patient samples has high clinical value. As current screening methods, such as the Pap smear test, are highly subjective and in many cases show low sensitivity and specificity, new supportive techniques are desirable to improve the quality of cervical cancer screening. In this study, vibrational spectroscopic techniques (Raman and Fourier Transform Infra Red absorption) have been applied to the investigation of four cervical cancer …

Go to article

Silver Nanoparticle Polymer Composite Based Humidity Sensor, Aoife Power, Tony Betts, John Cassidy Jan 2010

Silver Nanoparticle Polymer Composite Based Humidity Sensor, Aoife Power, Tony Betts, John Cassidy

Articles

Silver nanoparticles were synthesised by a chemical reduction process in order to produce an aqueous colloidal dispersion. The resulting colloids were then characterised by a combination of UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction and transmission electron microscopy and the nanoparticles were found to have an average diameter of 20–22 nm. The Ag/polymer nanocomposites were then applied to platinum interdigital electrodes as sensor coatings and the capability of the resulting sensor as a humidity detector investigated. With the application of 1 V, a current developed which was found to be directly proportional to humidity levels. The sensor gives a reversible, …

Go to article

A Study Of Accomodation Of Prosodic And Temporal Features In Spoken Dialogues In View Of Speech Technology Applications, Spyridon Kousidis Jan 2010

A Study Of Accomodation Of Prosodic And Temporal Features In Spoken Dialogues In View Of Speech Technology Applications, Spyridon Kousidis

Doctoral

Inter-speaker accommodation is a well-known property of human speech and human interaction in general. Broadly it refers to the behavioural patterns of two (or more) interactants and the effect of the (verbal and non-verbal) behaviour of each to that of the other(s). Implementation of this
behavior in spoken dialogue systems is desirable as an improvement on the naturalness of humanmachine interaction. However, traditional qualitative descriptions of accommodation phenomena do not provide sufficient information for such an implementation. Therefore, a quantitative
description of inter-speaker accommodation is required. This thesis proposes a methodology of monitoring accommodation during a human or humancomputer dialogue, …

Go to article

From Permutahedron To Aassociahedron, Colum Watt, Thomas Brady Jan 2010

From Permutahedron To Aassociahedron, Colum Watt, Thomas Brady

Articles

For each finite real reflection group $W$, we identify a copy of the type-$W$ simplicial generalised associahedron inside the corresponding simplicial permutahedron. This defines a bijection between the facets of the generalised associahedron and the elements of the type $W$ non-crossing partition lattice which is more tractable than previous such bijections. We show that the simplicial fan determined by this associahedron coincides with the Cambrian fan for $W$.

Go to article

The Similarity Problem For Indefinite Sturm-Liouville Operators With Periodic Coefficients, Aleksey Kostenko Jan 2010

The Similarity Problem For Indefinite Sturm-Liouville Operators With Periodic Coefficients, Aleksey Kostenko

Articles

We investigate the problem of similarity to a self-adjoint operator for $J$-positive Sturm-Liouville operators $L=\frac{1}{\omega}(-\frac{d^2}{dx^2}+q)$ with $2\pi$-periodic coefficients $q$ and $\omega$. It is shown that if 0 is a critical point of the operator $L$, then it is a singular critical point. This gives us a new class of $J$-positive differential operators with the singular critical point 0. Also, we extend the Beals and Parfenov regularity conditions for the critical point $\infty$ to the case of operators with periodic coefficients.

Go to article

Climbing Eements In Finite Coxeter Groups, Colum Watt, Thomas Brady, Aisling Kenny Jan 2010

Climbing Eements In Finite Coxeter Groups, Colum Watt, Thomas Brady, Aisling Kenny

Articles

We define the notion of a climbing element in a finite real reflection group relative to a total order on the reflection set and we characterise these elements in the case where the total order arises from a bipartite Coxeter element.

Go to article

Schrödinger Operators With Δ'Interactions And The Krein–Stieltjes String, Aleksey Kostenko, M. M. Malamud Jan 2010

Schrödinger Operators With Δ'Interactions And The Krein–Stieltjes String, Aleksey Kostenko, M. M. Malamud

Articles

We investigate one dimensional symmetric Schrödinger operator HX, β with δ' interactions of strength β = ⊂ on a discrete set X = ⊂ [0, b), b ≤ +∞ (xn ↑ b). We consider HX, β as an extension of the minimal operator Hmin := –d2/dx2 (\X) and study its spectral properties in the frame work of the extension theory by using the technique of boundary triplets and the corresponding Weyl functions. The construction of a boundary triplet for is given in the case d∗ := infn ∈ |xn – xn – 1| = 0. We show that spectral properties …

Go to article

Heat Transfer Through The Boundary Layer On A Moving Cylindrical Fibre, Brendan Redmond, David Mcdonnell Jan 2010

Heat Transfer Through The Boundary Layer On A Moving Cylindrical Fibre, Brendan Redmond, David Mcdonnell

Articles

This paper applies boundary layer theory to the process of manufacturing polymer fibres known as the melt spinning process. The rate of heat loss of the fibre during this process, characterised by the local Nusselt number, is evaluated by means of a Pohlhausen integral method.

Go to article

The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan Jan 2010

The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan

Articles

The aim of this research was to analyse the effects of three types of cheese whey permeate treatment on the antioxidant properties of fresh-cut tomatoes. Tomatoes were treated with whey permeate concentrate (PC), delactosed permeate (DP) and delactosed concentrate (DC), stored at 4 C for 10 days and compared to samples treated with the industry standard, chlorine (120 ppm). Samples treated with DP retained significantly higher antioxidant activity (FRAP) and total phenols (TP), when compared with those treated with PC and DC. DP showed significantly higher results than chlorine for DPPH, FRAP and TP. In DPPH assay, all whey permeate-treated …

Go to article

Motion In Augmented Reality Games: An Engine For Creating Plausible Physical Interactions In Augmented Reality Games, Brian Mac Namee, David Beaney, Qingqing Dong Jan 2010

Motion In Augmented Reality Games: An Engine For Creating Plausible Physical Interactions In Augmented Reality Games, Brian Mac Namee, David Beaney, Qingqing Dong

Articles

The next generation of Augmented Reality (AR) games will require real and virtual objects to coexist in motion in immersive game environments. This will require the illusion that real and virtual objects interact physically together in a plausible way. The Motion in Augmented Reality Games (MARG) engine described in this paper has been developed to allow these kinds of game environments. The paper describes the design and implementation of the MARG engine and presents two proof-of-concept AR games that have been developed using it. Evaluations of these games have been performed and are presented to show that the MARG engine …

Go to article

Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite Jan 2010

Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite

Doctoral

Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their successful synthesis. The dependence of grating performances in these nanocomposites on recording intensity, spatial frequency and zeolite concentration were studied. It was found that the incorporation of silicalite-1 nanoparticles or a small amount of zeolite A nanoparticles (up to …

Go to article

A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment, Paul Irving Jan 2010

A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment, Paul Irving

Doctoral

This phenomenographic study describes students’ approaches to learning and their perceptions of the learning environment in an introductory physics course which is taught using a problem-based learning approach. This research builds on previous studies which showed that these students develop a greater conceptual knowledge than their counterparts in a more traditional learning environment while others showed very little development even though they engaged fully with the pedagogy. This study aimed to examine and describe the students’ approaches to learning. The definitions of surface, strategic and deep approaches to learning are not appropriate in this context and could not be applied …

Go to article

Enhancing 3d Lidar Data Handling, Debra Laefer, Michela Bertolotto, Bianca Schoen-Phelan Jan 2010

Enhancing 3d Lidar Data Handling, Debra Laefer, Michela Bertolotto, Bianca Schoen-Phelan

Articles

more evident than in the limited capabilities of Spatial Information Systems (SIS) to manipulate data from aerial Light Detection and Ranging (LiDAR). Currently, multiple software packages are needed to conduct three-dimensional (3D) analysis of LiDAR data. This workflow heavily relies on importing and exporting different file formats, thus potentially losing accuracy and increasing costs. Ideally, all required functionality would be available within a single system. New functionalities in Oracle Spatial combined with our enhanced 3D-indexing for hosting and analysing offer a critical breakthrough in this area.

Go to article

Assessing The Application Of 3d Collaborative Interfaces Within An Immersive Virtual University, Gavin Mcardle, Bianca Schoen-Phelan, Michela Bortolotto Jan 2010

Assessing The Application Of 3d Collaborative Interfaces Within An Immersive Virtual University, Gavin Mcardle, Bianca Schoen-Phelan, Michela Bortolotto

Articles

The need to stimulate and engage students is of paramount importance within any learning scenario. Despite this, recent developments in online learning have failed to take this requirement into account. As a result e-learning courses which utilise traditional online learning management systems have a higher dropout rate than their classroom based counterparts. The attrition rate is attributed to boredom with the interfaces used to deliver learning material and also to the lack of opportunities to interact socially with others. Furthermore, being in a virtual environment imposes a whole new set of challenges onto users due to the distinct lack of …

Go to article

Mobile Mapping System Lidar Data Framework, P. Lewis, C. Mcelhinney, Bianca Schoen-Phelan, T. Mccarthy Jan 2010

Mobile Mapping System Lidar Data Framework, P. Lewis, C. Mcelhinney, Bianca Schoen-Phelan, T. Mccarthy

Articles

Mobile Mapping Systems (MMSs) for infrastructural monitoring and mapping arebecoming more prevalent as the availability and affordability of solutions that generate high accuracy geospatial data has matured.However, no existent methodology or systemexists where all theLiDAR, video, navigation,infrared and multispectraldata sources,collected from thismobile platform are integrated into a single, comprehensivedata management solution. Based on empirical experience there is a need for an MMS-data management framework where these types of data can be dynamically accessed and integratedto enable different projects with varying objectives todynamically accessdifferent MMS-data for, in one example, use in feature extraction algorithms. In this paper we introduce the LiDAR …

Go to article

Assessment Of The Accuracy Of An Ultrasound Elastography Liver Scanning System Using A Pva-Cryogel Phantom With Optimal Acoustic And Mechanical Properties, S. Cournane, Louise Cannon, Jacinta Browne, Andrew Fagan Jan 2010

Assessment Of The Accuracy Of An Ultrasound Elastography Liver Scanning System Using A Pva-Cryogel Phantom With Optimal Acoustic And Mechanical Properties, S. Cournane, Louise Cannon, Jacinta Browne, Andrew Fagan

Articles

The accuracy of a transient elastography liver-scanning ultrasound system was assessed using a novel application of PVA-cryogel as a tissue-mimicking material with acoustic and shear elasticity properties optimized to best represent those of liver tissue. Although the liver scanning system has been shown to offer a safer alternative for diagnosing liver cirrhosis through stiffness measurement, as compared to the liver needle biopsy exam, the scanner’s accuracy has not been fully established. The Young’s elastic modulus values of 5-6wt% PVA cryogel phantoms, also containing glycerol and 0.3μm Al2O3 and 3μm Al2O3, were measured using a ‘gold standard’ mechanical testing technique and …

Go to article

A Systematic Study Of The Dispersion Of Swnts In Organic Solvents, Qiaohuan Cheng, Sourabhi Debnath, Luke O'Neill, Theresa Hedderman, Elizabeth Gregan Jan 2010

A Systematic Study Of The Dispersion Of Swnts In Organic Solvents, Qiaohuan Cheng, Sourabhi Debnath, Luke O'Neill, Theresa Hedderman, Elizabeth Gregan

Articles

Dispersions of as-produced HiPco single-walled carbon nanotubes (SWNTs) in a series of organic solvents were prepared by dilution with the aid of tip sonication. Mild centrifugation (945 g) was carried out to remove large bundles. Atomic force microscopy (AFM) studies revealed that the bundle size decreased as the dispersion was diluted. By measuring the UV−vis−NIR absorption before and after centrifugation as a function of the concentration, the dispersion limit of SWNTs in each solvent can be determined. Correlations between the dispersion limit and solvent solubility parameters, including the Hildebrand solubility parameter and three-dimensional Hansen solubility parameters, are explored, demonstrating that …

Go to article

New Concept For Luminescent Solar Concentrators, Subhash Chandra, Sarah Mcormack, John Doran, Manus Kennedy, Amanda Chatten Jan 2010

New Concept For Luminescent Solar Concentrators, Subhash Chandra, Sarah Mcormack, John Doran, Manus Kennedy, Amanda Chatten

Conference Papers

We have studied the excitation rate of Lumogen Red dye molecules by enhanced local electromagnetic field of Au nanoparticles for thin film luminescent solar concentrator (LSCs).The localized enhanced electromagnetic field of Au nanoparticles leads to an increase the excitation rate, and consequently in emission rate of dye molecules. By varying the distance between Au nanoparticles and dye film we showed transition form quenching to enhancement in edge emission and resultant ISC current output of thin film LSCs. When dye molecules were placed in the range of enhanced electromagnetic field of Au nanoparticles. Two competing factors affected the edge emission of …

Go to article

Spectroscopic Analysis Of Therapeutic Drugs., Laura Perdisatt, Christine O'Connor, Samar Moqadasi, Luke O'Neill Jan 2010

Spectroscopic Analysis Of Therapeutic Drugs., Laura Perdisatt, Christine O'Connor, Samar Moqadasi, Luke O'Neill

Conference Papers

The aim of this project was to investigate the photochemistry of three new Ruthenium (II) complexes as possible therapeutics and their associated ligands. The objectives were to use the following spectroscopic techniques: Absorption, Emission and Raman spectroscopy. Luminescent lifetime measurements were obtained by laser studies (Nd:YAG laser and Time coupled single photon counting (TCSPC) ).

Go to article

Multi–Component Nls Models On Symmetric Spaces: Spectral Properties Versus Representations Theory, Vladimir Gerdjikov, Georgi Grahovski Jan 2010

Multi–Component Nls Models On Symmetric Spaces: Spectral Properties Versus Representations Theory, Vladimir Gerdjikov, Georgi Grahovski

Articles

The algebraic structure and the spectral properties of a special class of multicomponent NLS equations, related to the symmetric spaces of BD.I-type are analyzed. The focus of the study is on the spectral theory of the associated Lax operator to these nonlinear evolutionary equations for different fundamental representations of the underlying simple Lie algebra g. Special attention is paid to the spinor representation of the orthogonal Lie algebras of B type.

Go to article

On The Socles Of Characteristic Subgroups Of Abelian P-Groups, Brendan Goldsmith, Peter Danchev Jan 2010

On The Socles Of Characteristic Subgroups Of Abelian P-Groups, Brendan Goldsmith, Peter Danchev

Articles

Fully invariant subgroups of an Abelian p-group have been the object of a good deal of study, while characteristic subgroups have received somewhat less attention. Recently the socles of fully invariant subgroups have been studied and this led to the notion of a socle-regular group. The present work replaces the fully invariant subgroups with characteristic ones and leads in a natural way to the notion of a strongly socle-regular group. A surprising relationship, mirroring that between transitive and fully transitive groups, is obtained.

Go to article

From Permutahedron To Associahedron, Colum Watt, Thomas Brady Jan 2010

From Permutahedron To Associahedron, Colum Watt, Thomas Brady

Articles

For each finite real reflection group $W$, we identify a copy of the type-$W$ simplicial generalised associahedron inside the corresponding simplicial permutahedron. This defines a bijection between the facets of the generalised associahedron and the elements of the type-$W$ non-crossing partition lattice which is more tractable than previous such bijections. We show that the simplicial fan determined by this associahedron coincides with the Cambrian fan for $W$.

Go to article

A Computational Analysis Of Cognitive Effort, Luca Longo, Stephen Barrett Jan 2010

A Computational Analysis Of Cognitive Effort, Luca Longo, Stephen Barrett

Books/Book Chapters

Cognitive effort is a concept of unquestionable utility in understanding human behaviour. However, cognitive effort has been defined in several ways in literature and in everyday life, suffering from a partial understanding. It is common to say “Pay more attention in studying that subject” or “How much effort did you spend in resolving that task?”, but what does it really mean? This contribution tries to clarify the concept of cognitive effort, by introducing its main influencing factors and by presenting a formalism which provides us with a tool for precise discussion. The formalism is implementable as a computational concept and …

Go to article

Off To A Good Start: Using Clustering To Select The Initial Training Set In Active Learning, Rong Hu, Brian Mac Namee, Sarah Jane Delany Jan 2010

Off To A Good Start: Using Clustering To Select The Initial Training Set In Active Learning, Rong Hu, Brian Mac Namee, Sarah Jane Delany

Conference papers

Active learning (AL) is used in textual classification to alleviate the cost of labelling documents for training. An important issue in AL is the selection of a representative sample of documents to label for the initial training set that seeds the process, and clustering techniques have been successfully used in this regard. However, the clustering techniques used are nondeterministic which causes inconsistent behaviour in the AL process. In this paper we first illustrate the problems associated with using non-deterministic clustering for initial training set selection in AL. We then examine the performance of three deterministic clustering techniques for this task …

Go to article

Egal: Exploration Guided Active Learning For Tcbr, Rong Hu, Sarah Jane Delany, Brian Mac Namee Jan 2010

Egal: Exploration Guided Active Learning For Tcbr, Rong Hu, Sarah Jane Delany, Brian Mac Namee

Conference papers

The task of building labelled case bases can be approached using active learning (AL), a process which facilitates the labelling of large collections of examples with minimal manual labelling effort. The main challenge in designing AL systems is the development of a selection strategy to choose the most informative examples to manually label. Typical selection strategies use exploitation techniques which attempt to refine uncertain areas of the decision space based on the output of a classifier. Other approaches tend to balance exploitation with exploration, selecting examples from dense and interesting regions of the domain space. In this paper we present …

Go to article

Svm Based Active Learning With Exploration, Patrick Lindstrom, Rong Hu, Sarah Jane Delany, Brian Mac Namee Jan 2010

Svm Based Active Learning With Exploration, Patrick Lindstrom, Rong Hu, Sarah Jane Delany, Brian Mac Namee

Conference papers

No abstract provided.

Go to article

An Empirically-Based Model For Perspective Selection In Route-Finding Dialogues, Robert J. Ross, Kavita E. Thomas Jan 2010

An Empirically-Based Model For Perspective Selection In Route-Finding Dialogues, Robert J. Ross, Kavita E. Thomas

Conference papers

In this work we aim to computationally model the extent to which certain empirical factors affect spatial perspective selection as used in route-finding dialogues. In such dialogues, both interlocutors need to adopt a spatial perspective in which to describe movement direction. In map-based tasks such as the one we are concerned with, two perspective choices are typically available, i.e., route perspective, where projective terms are defined with respect to the perspective of the route follower themselves, e.g., ``go to your right'', or survey perspective, where projective terms are defined with respect to a global or allocentric perspective, e.g., ``go down'', …

Go to article

First Prev Next Last