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Articles 1861 - 1890 of 2383

Full-Text Articles in Physical Sciences and Mathematics

Context Aware Smart Classroom For Real Time Configuration Of Computer Rooms, Paula Kelly, Peter Daly, Ciaran O'Driscoll Oct 2009

Context Aware Smart Classroom For Real Time Configuration Of Computer Rooms, Paula Kelly, Peter Daly, Ciaran O'Driscoll

9th. IT & T Conference

The Context Aware Smart Classroom (CASC) is a classroom that responds to lecturers and student groups based on preset policies and the lecture timetables. CASC has been enhanced in two ways: initially to support the real-time software configuration of computers as required by specific laboratory activities; secondly to improve the decision making using knowledge engineering techniques. This paper outlines the design, implementation and evaluation of an enhanced system, CASC for Software Configuration (CASC–SC). Context aware environments respond in a pseudo-intelligent manner depending on the identity of occupants, particular location, desired activity and specific time. With the pervasive nature of personal …

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Voshm: A Velocity Optimized Seamless Handover Mechanism For Wimax Networks, Chi Ma, Enda Fallon, Yansong Qiao Oct 2009

Voshm: A Velocity Optimized Seamless Handover Mechanism For Wimax Networks, Chi Ma, Enda Fallon, Yansong Qiao

9th. IT & T Conference

For seamless handover in heterogeneous wireless networks, service continuity and minimal handover disruption time are the primary requirements. The emerging Media Independent Handover (MIH) standard proposes to address these requirements through the introduction of link performance prediction features. In particular the MIH Event Service introduces a Link_Going_Down event which utilizes L2 performance characteristics to trigger predictive events. While the MIH standard proposes a framework by which L2 events can be communicated to the upper layer, it does provide detail on the performance characteristics which trigger these events. In this paper, we design a MIH based Velocity Optimized Seamless Handover Mechanism …

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Intelligent Virtual Agent: Creating A Multi-Modal 3d Avatar Interface, Mark Dunne, Brian Mac Namee, John D. Kelleher Oct 2009

Intelligent Virtual Agent: Creating A Multi-Modal 3d Avatar Interface, Mark Dunne, Brian Mac Namee, John D. Kelleher

9th. IT & T Conference

Human-computer interactions can be greatly enhanced by the use of 3D avatars, representing both human users and computer systems in 3D virtual spaces. This allows the human user to interface with the computer system in a natural and intuitive human-to-human dialog (human face-to-face conversation). Hence, continuing to blur the boundaries between the real and virtual worlds. This proposed avatar system will go a step further and will use a camera to track the user’s head and eye movements during the dialog. This information will help to build rapport between the user and computer system by registering the user’s emotional state …

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Photopolymers: Beyond The Standard Approach To Photosensitisation, Izabela Naydenova, Suzanne Martin, Vincent Toal Sep 2009

Photopolymers: Beyond The Standard Approach To Photosensitisation, Izabela Naydenova, Suzanne Martin, Vincent Toal

Articles

A photopolymerizable material for use in the visible normally consists of a dye sensitizer, a free radical generator, monomer/monomers and, optionally, a binder, and is prepared usually as a dry or liquid film. Upon illumination with light of appropriate wavelength, a photopolymerisation reaction is triggered, leading to a change in the film’s refractive index. Because the presence of the dye is essential, the film is usually made sensitive to light during its preparation. Here we separate the film preparation and the sensitisation processes. In this way the photopolymerisation process can be used to detect dye labelled analytes, providing an alternative …

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Spectroscopic Investigation Of The Anatase-To-Rutile Transformation Of Sol-Gel Synthesised Tio2 Photocatalysts, Nicholas Nolan, Suresh Pillai, Michael Seery Sep 2009

Spectroscopic Investigation Of The Anatase-To-Rutile Transformation Of Sol-Gel Synthesised Tio2 Photocatalysts, Nicholas Nolan, Suresh Pillai, Michael Seery

Articles

Among the three major phases in titania, anatase is reported to be a better photocatalytically active phase. Anatase to rutile transformations, under normal conditions, usually occurs at a temperatue range of 600- 700 °C. Various chemical additives have previously been employed to extend the anatase transition to higher temperatures. Effect of employing various concentrations of formic acid and water on phase transition has systematically been studied by XRD, FTIR and Raman spectroscopy. A considerably higher anatase phase (41%) has been obtained at 800 ºC and 10% anatase composition is retained after annealing the materials at 900 ºC for the optimised …

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Metal-Induced Bystander Effects: Mechanism And Implicationis., Nicola Cogan Sep 2009

Metal-Induced Bystander Effects: Mechanism And Implicationis., Nicola Cogan

Doctoral

The radiation-induced bystander effect is a phenomenon known to occur post irradiation, characterised by the induction of biological effects in unirradiated cells as a result of receiving signals from irradiated cells or their culture medium. Chemicalinduced bystander effects are poorly characterised and there are no reports of a bystander effect induced by metals. Heavy metals and in particular chromium (VI) are known to cause persistent genomic instability. For the first time, this study provides evidence that a short, low-dose exposure of human fibroblasts to chromium (VI) causes a bystander effect in human fibroblasts that persists for at least thirty days …

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Stochastic Particle Acceleration In The Lobes Of Giant Radio Galaxies, Stephen O'Sullivan, Brian Reville, Andrew Taylor Sep 2009

Stochastic Particle Acceleration In The Lobes Of Giant Radio Galaxies, Stephen O'Sullivan, Brian Reville, Andrew Taylor

Articles

We investigate the acceleration of particles by Alfv ́en waves via the second-order Fermi process in the lobes of giant radio galaxies. Such sites are candidates for the accelerators of ultra-high-energy cosmic rays (UHECR). We focus on the nearby Fanaroff–Riley type I radio galaxy Centaurus A. This is motivated by the coincidence of its position with the arrival direction of several of the highest energy Auger events. The conditions necessary for consistency with the acceleration time-scales predicted by quasi-linear theory are reviewed. Test particle calculations are performed in fields which guarantee electric fields with no component parallel to the local …

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Self-Authentication Of Audio Signals By Chirp Coding, Jonathan Blackledge, Eugene Coyle Sep 2009

Self-Authentication Of Audio Signals By Chirp Coding, Jonathan Blackledge, Eugene Coyle

Conference papers

This paper discusses a new approach to ‘watermarking’ digital signals using linear frequency modulated or ‘chirp’ coding. The principles underlying this approach are based on the use of a matched filter to provide a reconstruction of a chirped code that is uniquely robust in the case of signals with very low signal-to-noise ratios. Chirp coding for authenticating data is generic in the sense that it can be used for a range of data types and applications (the authentication of speech and audio signals, for example). The theoretical and computational aspects of the matched filter and the properties of a chirp …

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The Very Basics Of Sustainability - An Alternative Viewpoint, Jim Mcgovern Aug 2009

The Very Basics Of Sustainability - An Alternative Viewpoint, Jim Mcgovern

Other resources

This paper examines the context and meaning of the term ‘sustainability’, the factors that determine and govern climate on Earth, the population of the Earth and its trends and influencers, the requirements for sustaining life and the options that are available to humankind. Some viewpoints are presented that are alternative to ‘conventional alternative’ thinking. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’ and also argues that humankind needs to face …

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Nonideal Magnetohydrodynamic Turbulent Decay In Molecular Clouds, Turlough Downes, Stephen O'Sullivan Aug 2009

Nonideal Magnetohydrodynamic Turbulent Decay In Molecular Clouds, Turlough Downes, Stephen O'Sullivan

Articles

It is well known that non-ideal magnetohydrodynamic effects are important in the dynamics of molecular clouds: both ambipolar diffusion and possibly the Hall effect have been identified as significant. We present the results of a suite of simulations with a resolution of 512-cubed of turbulent decay in molecular clouds incorporating a simplified form of both ambipolar diffusion and the Hall effect simultaneously. The initial velocity field in the turbulence is varied from being super-Alfvénic and hypersonic, through to trans-Alfvénic but still supersonic.

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The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern Aug 2009

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …

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Assessment Of The Embodied Co2eq In Buildings Towards A Sustainable Building Design And Construction, Adolf Acquaye, Aidan Duffy, Biswajit Basu Jul 2009

Assessment Of The Embodied Co2eq In Buildings Towards A Sustainable Building Design And Construction, Adolf Acquaye, Aidan Duffy, Biswajit Basu

Conference Papers

Research studies have shown that the initial energy embodied in a building can be as much as 67% of the operational energy over a 25 year period. With growing global concerns over material and resource consumption and the emissions of CO2 into the atmosphere, the energy embodied in buildings constructed in town and cities becomes important and one of the key issues that needs to be tackled in the design stages in order to strive towards sustainable buildings design. In this paper, a hybrid embodied carbon dioxide equivalent (CO2eq) methodology used to assess the CO2eq embodied in buildings is presented. …

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The Potential Use Of Slow-Down Technology To Improve Pronounciation Of English For International Communication, Bunny Richardson Jul 2009

The Potential Use Of Slow-Down Technology To Improve Pronounciation Of English For International Communication, Bunny Richardson

Doctoral

The focus of this research is on oral communication between L1 (first language) and L2 (second language) English users - to determine whether an algorithm which slows down speech can increase the intelligibility of speech between interlocutors for EIC (English for International Communication). The slow-down facility is a CALL tool which slows down speech without tonal distortion. It allows English language learners more processing time to hear individual phonemes as produced in the stream of connected speech, to help them hear and produce phonemes more accurately and thus more intelligibly. The study involved five tests, all concerned with the intelligibility …

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Evolution Versus Revolution As A Strategy For Thin Client Acceptance: Case Study, Paul Doyle, Mark Deegan, Ciaran O'Driscoll Jul 2009

Evolution Versus Revolution As A Strategy For Thin Client Acceptance: Case Study, Paul Doyle, Mark Deegan, Ciaran O'Driscoll

Conference papers

Thin Clients have evolved from simple text based CRT dumb terminal devices in the 1960s, into a sophisticated architecture encompassing hardware, software, networks and protocols. However despite this recent evolution the Thin Client model has yet to re-emerge as a relevant design in an IT industry where Fat Clients (desktops and laptops) thrive. This paper describes two case studies performed within the Technological University Dublin School of Computing, focused on the issue of student acceptance of this technology. The first case study provides a dedicated single service Thin Client implementation, while the second case study adopts a process of coexistence …

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A Context-Aware Approach Based On Self-Organizing Maps To Study Web-Users' Tendencies From Their Behaviour, Luca Longo, Stephen Barrett Jun 2009

A Context-Aware Approach Based On Self-Organizing Maps To Study Web-Users' Tendencies From Their Behaviour, Luca Longo, Stephen Barrett

Conference papers

In the context of a highly volatile web of uneven quality, the identification of content deemed valuable by end users is of paramount importance. Where page content undergoes rapid change, this issue is particularly challenging. Web browsing activity represents a unique source of context by which the value of web pages can be determined via an assessment of individual user interactions, such as scrolling, clicking, saving and so forth. Over time, this data set forms a pattern of activity which can be mined for meaning. In this paper we present an approach to web content, based on Kohonen mapping, used …

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Applying Computational Models Of Spatial Prepositions To Visually Situated Dialog, John D. Kelleher, Fintan Costello Jun 2009

Applying Computational Models Of Spatial Prepositions To Visually Situated Dialog, John D. Kelleher, Fintan Costello

Articles

This article describes the application of computational models of spatial prepositions to visually situated dialog systems. In these dialogs, spatial prepositions are important because people often use them to refer to entities in the visual context of a dialog. We first describe a generic architecture for a visually situated dialog system and highlight the interactions between the spatial cognition module, which provides the interface to the models of prepositional semantics, and the other components in the architecture. Following this, we present two new computational models of topological and projective spatial prepositions. The main novelty within these models is the fact …

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Development Of Renal Phantoms For The Evaluation Of Current And Emerging Ultrasound Technology, Deirdre King Jun 2009

Development Of Renal Phantoms For The Evaluation Of Current And Emerging Ultrasound Technology, Deirdre King

Doctoral

The primary aim of this project was to develop novel anatomically realistic renal phantoms for the evaluation of current and emerging ultrasound techniques capable of diagnosing all grades of renal artery stenosis. Renal artery stenosis is considered the most common cause of potentially curable secondary hypertension which if left untreated can lead to renal failure. Its early detection is very important as it offers the possibility of various drug treatments, which are considerably less invasive and poses less risk to the patient. Computer-aided modelling techniques were used to generate a range of anatomically realistic phantoms of the renal artery from …

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Characterisation Of The Humidity And Temperature Responses Of A Reflection Hologram Recorded In Acrylamide-Based Photopolymer, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin May 2009

Characterisation Of The Humidity And Temperature Responses Of A Reflection Hologram Recorded In Acrylamide-Based Photopolymer, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin

Articles

The humidity and temperature responses of a reflection hologram recorded in a self-processing photopolymer layer have been characterised by measurement of the position of the maximum intensity in the spectral response of the hologram. It has been demonstrated that such a hologram can be used for indication of the relative humidity (RH) in a specific temperature range. The operational range and reversibility of the holograms have been characterised in a controlled humidity and temperature environment. The humidity studies were carried out in the range from 10 to 80% RH and the temperature range under study was 15 – 50 ºC.

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Covariant Relativistic Quantum Mechanics Analysis Of A Linearly Accelerated Scalar Particle, Karol Mcdonald May 2009

Covariant Relativistic Quantum Mechanics Analysis Of A Linearly Accelerated Scalar Particle, Karol Mcdonald

Doctoral

A covariant formalism of Relativistic Quantum Mechanics is demonstrated, through it's de- velopment and application. The Relativistic Case is shown to follow a similar structure to the established Non-Relativistic formalism. Reasons for preferring the new covariant formalism over the established method are presented. Solutions to the case of a scalar particle in a one-dimensional field are presented. The Relativistic Energy Eigenfunction is derived. Results are generated from initial Gaussian states via a Green's Function method. A Green's Function for the system is derived and applied. The solution to the Quantum System is shown to follow a scaled version of the …

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Tight Lower Bound For The Sparse Travelling Salesman Problem, Fredrick Mtenzi May 2009

Tight Lower Bound For The Sparse Travelling Salesman Problem, Fredrick Mtenzi

Conference papers

The Sparse Travelling Salesman Problem (Sparse TSP) which is a variant of the classical Travelling Salesman Problem (TSP) is the problem of finding the shortest route of the salesman when visiting cities in a region making sure that each city is visited at least once and returning home at the end. In the Sparse TSP, the distance between cities may not obey the triangle inequality; this makes the use of algorithms and formulations designed for the TSP to require modifications in order to produce near-optimal results. A lower bound for optmisation problems gives us the quality guarantee of the near-optimal …

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Samats: Texture Extraction Explained, Joe Hegarty, James Carswell Feb 2009

Samats: Texture Extraction Explained, Joe Hegarty, James Carswell

Conference papers

The creation of detailed 3D buildings models, and to a greater extent the creation of entire city models, has become an area of considerable research over the last couple of decades. The accurate modeling of buildings has LBS (Location Based Services) applications in entertainment, planning, tourism and e-commerce to name just a few. Many modeling systems deployed to date require manual correspondences to be made across the image set in order to determine the models 3D structure. This paper describes SAMATS, a Semi-Automated Modelling and Texturing System, which has the capability of producing geometrically accurate and photorealistic building models without …

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Swcnt Suppress Inflammatory Mediator Responses In Human Lung Epithelium In Vitro, Eva Herzog, Hugh Byrne, Maria Davoren, Anke-Gabriele Lenz, Albert Duschl, Gertie Janneke Oostingh Feb 2009

Swcnt Suppress Inflammatory Mediator Responses In Human Lung Epithelium In Vitro, Eva Herzog, Hugh Byrne, Maria Davoren, Anke-Gabriele Lenz, Albert Duschl, Gertie Janneke Oostingh

Articles

Single walled carbon nanotubes have gained enormous popularity due to a variety of potential applications which will ultimately lead to increased human and environmental exposure to these nanoparticles. This study was carried out in order to evaluate the inflammatory response of immortalised and primary human lung epithelial cells (A549 and NHBE) to single walled carbon nanotube samples (SWCNT). Special focus was placed on the mediating role of lung surfactant on particle toxicity. The toxicity of SWCNT dispersed in cell culture medium was compared to that of nanotubes dispersed in dipalmitoylphosphatidylcholine (DPPC, the main component of lung lining fluid). Exposure was …

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Spectroscopic Imaging Of Quantum Dot Cellular Interactions, Lorenzo Salford Feb 2009

Spectroscopic Imaging Of Quantum Dot Cellular Interactions, Lorenzo Salford

Masters

Quantum dots (QDs) are a diverse class of engineered nanomaterials that have great potential for use as agents in imaging, diagnostics and drug-delivery because of their intense and photostable fluorescence. Advances in the field of nanotoxicology, however, have recently identified potential risks and hazards associated with exposure to QDs. The main purpose of this research is to investigate the capabilities of a synergistic range of different techniques, including cytotoxicity assays, confocal microscopy and vibrational spectroscopy, to probe their interaction with Biological systems. With the combination of these techniques it is hoped to understand the mechanisms of the interaction of QDs …

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Modelling Groups Of Plausible Virtual Pedestrians, Christopher Peters, Cathy Ennis, Carol O'Sullivan Jan 2009

Modelling Groups Of Plausible Virtual Pedestrians, Christopher Peters, Cathy Ennis, Carol O'Sullivan

Articles

No abstract provided.

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Talking Bodies: Sensitivity To Desynchronization Of Conversations, Rachel Mcdonnell, Cathy Ennis, Simon Dobbyn, Carol O'Sullivan Jan 2009

Talking Bodies: Sensitivity To Desynchronization Of Conversations, Rachel Mcdonnell, Cathy Ennis, Simon Dobbyn, Carol O'Sullivan

Articles

In this article, we investigate human sensitivity to the coordination and timing of conversational body language for virtual characters. First, we captured the full body motions (excluding faces and hands) of three actors conversing about a range of topics, in either a polite (i.e., one person talking at a time) or debate/argument style. Stimuli were then created by applying the motion-captured conversations from the actors to virtual characters. In a 2AFC experiment, participants viewed paired sequences of synchronized and desynchronized conversations and were asked to guess which was the real one. Detection performance was above chance for both conversation styles …

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Synthesis And Spectroscopic Analysis Of Therapeutic Ru(Ii) Complexes, Samar Moqadasi, Laura Perdisatt, Christine O'Connor, Luke O'Neill Jan 2009

Synthesis And Spectroscopic Analysis Of Therapeutic Ru(Ii) Complexes, Samar Moqadasi, Laura Perdisatt, Christine O'Connor, Luke O'Neill

Conference Papers

The aim of this study is to synthesise and characterise new ligands based on a 1,10-Phenanthroline-5,6-dione backbone and their respective Ru(II) complexes; Ru(bpy)2mfmp, Ru(bpy)2fmp and Ru(bpy)2NO2-mp as shown in figure 1.The synthesis of the ligands will be discussed and a variety of Ru(II) complexes. A brief insight of the electronic and NMR spectroscopy will be presented along with preliminary photochemical results such as extinction coefficients, quantum yields and luminescence lifetimes. Ruthenium complexes have well established synthetic and photochemical properties.1The objective of this work is to synthesise Ru(II) complexes for the applications of potential therapeutics. In order to establish their uses …

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Sustainable Trail Management: A Transdisciplinary Approach, Sinead O'Connor-Gotra Jan 2009

Sustainable Trail Management: A Transdisciplinary Approach, Sinead O'Connor-Gotra

Theses, Doctoral

The research reported has created a holistic model for sustainable trail management that is broader than the quantitative assessment of ecological trail degradation. The range of quantitative and qualitative results gathered show that a more realistic treatment of sustainable trail management needs is achieved through a qualitative, participative and flexible research process. The investigation focuses primarily on the assessment of trail degradation in the uplands of Co. Wicklow, Ireland where signs of deterioration have been observed as a consequence of recreational use. The nature and extent of trail degradation was assessed using a variety of techniques including qualitative and quantitative …

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Poisson Structures Of Equations Associated With Groups Of Diffeomorphisms, Rossen Ivanov Jan 2009

Poisson Structures Of Equations Associated With Groups Of Diffeomorphisms, Rossen Ivanov

Conference papers

A class of equations describing the geodesic flow for a right-invariant metric on the group of diffeomorphisms of Rn is reviewed from the viewpoint of their Lie-Poisson structures. A subclass of these equations is analogous to the Euler equations in hydrodynamics (for n = 3), preserving the volume element of the domain of fluid flow. An example in n = 1 dimension is the Camassa-Holm equation, which is a geodesic flow equation on the group of diffeomorphisms, preserving the H1 metric.

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Two Component Integrable Systems Modelling Shallow Water Waves, Rossen Ivanov Jan 2009

Two Component Integrable Systems Modelling Shallow Water Waves, Rossen Ivanov

Conference papers

Our aim is to describe the derivation of shallow water model equations for the constant vorticity case and to demonstrate how these equations can be related to two integrable systems: a two component integrable generalization of the Camassa-Holm equation and the Kaup - Boussinesq system.

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Online Support And Online Assessment For Teaching And Learning Chemistry, Claire M. Mcdonnell, Natasa Brouwer Jan 2009

Online Support And Online Assessment For Teaching And Learning Chemistry, Claire M. Mcdonnell, Natasa Brouwer

Books/Book chapters

In this chapter, examples of innovative approaches that use educational technology to support active learning in chemistry lectures, tutorials and laboratory sessions are considered. The scope of the chapter is limited to blended learning. The strengths and weaknesses of e-learning are examined and the options available for online assessment using electronic tests and e-portfolios are discussed. In addition to the literature references provided in the chapter, several examples of good practice involving the implementation of information and communication technology for chemistry teaching in higher education are incorporated. A list of online resources for lecturers is also included.

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