Physical Sciences and Mathematics Commons^™

The Generalised Zakharov-Shabat System And The Gauge Group Action, Georgi Grahovski

Articles

The generalized Zakharov-Shabat systems with complex-valued non-regular Cartan elements and the systems studied by Caudrey, Beals and Coifman (CBC systems) and their gauge equivalent are studied. This study includes: the properties of fundamental analytical solutions (FAS) for the gauge-equivalent to CBC systems and the minimal set of scattering data; the description of the class of nonlinear evolutionary equations, solvable by the inverse scattering method, and the recursion operator, related to such systems; the hierarchies of Hamiltonian structures. The results are illustrated on the example of the multi-component nonlinear Schrodinger (MNLS) equations and the corresponding gauge-equivalent multi-component Heisenberg ferromagnetic (MHF) type …

Significantly Reducing The Processing Times Of High-Speed Photometry Data Sets Using A Distributed Computing Model, Paul Doyle, Fredrick Mtenzi, Niall Smith, Adrian Collins, Brendan O'Shea

Other

The scientific community is in the midst of a data analysis crisis. The increasing capacity of scientific CCD instrumentation and their falling costs is contributing to an explosive generation of raw photometric data. This data must go through a process of cleaning and reduction before it can be used for high precision photometric analysis. Many existing data processing pipelines either assume a relatively small dataset or are batch processed by a High Performance Computing centre. A radical overhaul of these processing pipelines is required to allow reduction and cleaning rates to process terabyte sized datasets at near capture rates using …

Integrable Models For Shallow Water With Energy Dependent Spectral Problems, Rossen Ivanov, Tony Lyons

Articles

We study the inverse problem for the so-called operators with energy depending potentials. In particular, we study spectral operators with quadratic dependence on the spectral parameter. The corresponding hierarchy of integrable equations includes the Kaup–Boussinesq equation. We formulate the inverse problem as a Riemann–Hilbert problem with a Z₂ reduction group. The soliton solutions are explicitly obtained.

Profiling Instances In Noise Reduction, Sarah Jane Delany, Nicola Segata, Brian Macnamee

Articles

The dependency on the quality of the training data has led to significant work in noise reduction for instance-based learning algorithms. This paper presents an empirical evaluation of current noise reduction techniques, not just from the perspective of their comparative performance, but from the perspective of investigating the types of instances that they focus on for re- moval. A novel instance profiling technique known as RDCL profiling allows the structure of a training set to be analysed at the instance level cate- gorising each instance based on modelling their local competence properties. This profiling approach o↵ers the opportunity of investigating …

Sms Spam Filtering: Methods And Data, Sarah Jane Delany, Mark Buckley, Derek Greene

Articles

Mobile or SMS spam is a real and growing problem primarily due to the availability of very cheap bulk pre-pay SMS packages and the fact that SMS engenders higher response rates as it is a trusted and personal service. SMS spam filtering is a relatively new task which inherits many issues and solu- tions from email spam filtering. However it poses its own specific challenges. This paper motivates work on filtering SMS spam and reviews recent devel- opments in SMS spam filtering. The paper also discusses the issues with data collection and availability for furthering research in this area, analyses …

The Role Of Mathematics In Engineering Practice And In The Formation Of Engineers, Eileen Goold, F. Devitt

Conference papers

I n Ireland, the number of school leavers pursuing professional engineering careers has been declining almost continuously over twenty years. Students wishing to pursue professional engineering degree courses are required to demonstrate proficiency in secondary school mathematics at the higher level. Yet, only a 16% minority of secondary school mathematics students in Ireland takes the Leaving Certificate mathematics exam at the higher level. It is widely thought that mathematics is the “key academic hurdle” in producing a supply of engineering graduates.

Personality Modulates The Effects Of Emotional Arousal And Valence On Brain Activation, Elizabeth G. Kehoe, John M. Toomey, Joshua H. Balsters, Arun L.W. Bokde

Articles

The influence of personality on the neural correlates of emotional processing is still not well characterized. We investigated the relationship between extraversion and neuroticism and emotional perception using functional magnetic resonance imaging (fMRI) in a group of 23 young, healthy women. Using a parametric modulation approach, we examined how the blood oxygenation level dependent (BOLD) signal varied with the participants’ ratings of arousal and valence, and whether levels of extraversion and neuroticism were related to these modulations. In particular, we wished to test Eysenck's biological theory of personality, which links high extraversion to lower levels of reticulothalamic–cortical arousal, and neuroticism …

Effect Of Motion On The Adc Quantification Accuracy Of Whole-Body Dwibs, A. Stone, Jacinta Browne, Brian Lennon, James Meaney, Andrew Fagan

Articles

y

Diffusion-weighted whole-body imaging with background body signal subtraction was introduced as a qualitative approach to detecting metastases in the body. A liver-mimicking phantom with embedded tumours that could be moved to replicate respiratory motion was developed to assess its ability to accurately quantify ADC values.

RESULTS:

Mean tumour ADC values were unaltered by the motion; however, a significant (p < 0.05) increase in the spread of ADC values was measured, even for relatively large tumours.

CONCLUSIONS:

These findings may be of significance in cancer therapy monitoring where subtle changes in ADC histograms may reveal changes in tumour heterogeneity.

New Non-Toxic Holographic Photopolymer Material, Dervil Cody, Izabela Naydenova, Emilia Mihaylova

Articles

There is an increasing need for environmentally friendly holographic recording materials which can be produced in bulk with little risk to the health of workers in manufacturing. This is why the development of non-toxic photopolymer materials is crucial, and has attracted attention in recent years. Composition and preliminary characterization of a new non-toxic photopolymer material are presented. It operates well at a range of spatial frequencies, and achieves diffraction efficiencies and refractive index modulation comparable to the known acrylamide-based photopolymers.

Comparison Of Micro- And Nanoscale Fe+3-Containing (Hematite) Particles For Their Toxicological Properties In Human Lung Cells In Vitro, Kunal Bhattacharya, Eik Hoffmann, Roel Schins, Jens Boertz, Eva-Maria Prantl, Gerrit Alink, Hugh Byrne, Thomas Kuhlbusch, Qamar Rahman, Hartmut Wiggers, Christof Schulz, Elke Dopp

Articles

The specific properties of nanoscale particles, large surface-to-mass ratio and highly reactive surfaces, have increased their commercial application in many fields. However, the same properties are also important for the interaction and bio-accumulation of the non-/biodegradable nanoscale particles in a biological system and are a cause for concern. Hematite (α-Fe2O3), being a mineral form of Fe(III) oxide, is one of the most used iron oxides besides magnetite. The aim of our study was the characterization and comparison of biophysical reactivity and toxicological effects of α-Fe2O3 nano- (d < 100 nm) and microscale (d < 5 μm) particles in human lung cells. Our study demonstrates that the surface reactivity of nanoscale α-Fe2O3 differs to that of microscale particles with respect to the state of agglomeration, radical formation potential, and cellular toxicity. The presence of proteins in culture medium and agglomeration were found to affect the catalytic properties of the hematite nano- and microscale particles. Both the nano- and microscale α-Fe2O3 particles were actively taken up by human lung cells in vitro, although, they were not found in the nuclei and mitochondria. …

An Improved Flood Forecasting Model Of The Blue Nile River In Sudan, Gamal Abdo, Ahmed Nasr

Articles

Reliable flood predictions with a reasonable lead time in the Blue Nile River in Sudan are vitally important to avoid catastrophic damages due to flooding of this river and the main River Nile. A HEC-RAS model was initially applied to the Blue Nile by representing the river as a single reach. The resulting original model was subsequently improved by including the two tributaries of the river, Rahad and Dindir, and also the two existing reservoirs, Rosaries and Sinnar, to the model. The original and the improved models were calibrated using 1988 flood data for the period from June to September …

Evaluating The Benefits Of Octree-Based Indexing For Lidar Data, Abu Saleh Mohammad Mosa, Bianca Schoen-Phelan, Michela Bertolotto, Debra Laefer

Articles

Very large true three-dimensional (3D) point datasets, as opposed to the previously common 2.5D data sets, are progressively more common nowadays, such as from Light Detection and Ranging (LiDAR). Increasingly, attempts are made to exploit these 3D point data sets beyond mere visualization. However, current Spatial Information Systems provide only limited 3D support. Even commercial systems advertising in-built, 3D data types provide only minimal functionality. Particularly, there is no effective means of indexing large 3D point datasets, which is crucial for efficient analysis and engineering usage. Also many datasets are information rich (e.g. contain color or some other associated semantic …

Developing A Promo Video In Premiere Elements: A Day In Dublin, Jerome Casey

Instructional Guides

No abstract provided.

On Projection-Invariant Subgroups Of Abelian P-Groups, Brendan Goldsmith

Articles

A subgroup P of an Abelian p-group G is said to be projection-invariant in G if Pf is contained in P for all idempotent endomorphisms f. Clearly fully invariant subgroups are projection invariant, but the converse is not true in general. Hausen and Megibben have shown that in many familiar situations these two concepts coincide. In a different direction, the authors have previously introduced the notions of socle-regular and strongly socle-regular groups by focussing on the socles of fully invariant and characteristic subgroups of p-groups. In the present work the authors examine the socles of projection-invariant subgroups of Abelian p-groups.

The Generalised Zakharov-Shabat System And The Gauge Group Action, Georgi Grahovski

Articles

The generalized Zakharov–Shabat systems with complex-valued non-regular Cartan elements and the systems studied by Caudrey, Beals and Coifman (CBC systems) and their gauge equivalent are studied. This study includes: the properties of fundamental analytical solutions (FAS) for the gauge-equivalent to CBC systems and the minimal set of scattering data; the description of the class of nonlinear evolutionary equations, solvable by the inverse scattering method, and the recursion operator, related to such systems; the hierarchies of Hamiltonian structures. The results are illustrated on the example of the multi-component nonlinear Schr¨odinger (MNLS) equations and the corresponding gauge-equivalent multi-component Heisenberg ferromagnetic (MHF) type …

Formalising Human Mental Workload As Non-Montonic Concept For Adaptive And Personalised Web-Design, Luca Longo

Books/Book Chapters

Web Design has been evolving with Web-based systems becoming more complex and structured due to the delivery of personalised information adapted to end-users. Although information presented can be useful and well formatted, people have little mental workload available for dealing with unusable systems. Subjective mental workload assessments tools are usually adopted to measure the impact of Web-tasks upon end-users thanks to their ease of use and are aimed at supporting design practices. The Nasa Task Load Index subjective procedure has been taken as a reference technique for measuring mental workload, but it has a background in aircraft cockpits, supervisory and …

Effect On Diagnostic Image Quality Of 3d Warping Registration Algorithms For Mr Angiography In The Lower Legs, Andrew Fagan, Daniel Foley, Jacinta Browne, Barry Sheane, Dearbhail O'Driscoll, Niall Sheehy, James Meaney

Articles

No abstract provided.

Impaired Cleanance And Enhanced Pulmonary Inflammatory/Fibrotic Response To Carbon Nanotubes In Myeloperoxidase-Deficient Mice, Anna A. Shvedova, Alexandr A. Kapralov, Wei Hong Feng, Elena R. Kisin, Ashley R. Murray, Robert R. Mercer, Claudette M. St. Croix, Megan A. Lang, Simon C. Watkins, Nagarjun V. Konduru, Brett L. Allen, Jennifer Conroy, Gregg P. Kotchey, Bashir M. Mohamed, Aidan Meade, Yuri Volkov, Alexander Star, Bengt Fadeel, Valerian E. Kagan

Articles

Advancement of biomedical applications of carbonaceous nanomaterials is hampered by their biopersistence and pro-inflammatory action in vivo. Here, we used myeloperoxidase knockout B6.129X1-MPO (MPO k/o) mice and showed that oxidation and clearance of single walled carbon nanotubes (SWCNT) from the lungs of these animals after pharyngeal aspiration was markedly less effective whereas the inflammatory response was more robust than in wild-type C57Bl/6 mice. Our results provide direct evidence for the participation of MPO – one of the key-orchestrators of inflammatory response – in the in vivo pulmonary oxidative biodegradation of SWCNT and suggest new ways to control the biopersistence …

Characterisation Of The Acoustic Output Of Three Sonoporation Drug Delivery Ultrasound Systems Using An Acoustic Radiation Force Balance, Tapihwa Mabvaro, Jacinta Browne

Articles

No abstract provided.

The Effects Of Fatty Desposits On The Accuracy Of The Fibroscan Liver Transient Elastography Ultrasound System, S. Cournane, Jacinta Browne, Andrew Fagan

Articles

A new generation of ultrasound transient elastography (TE) systems have emerged which exploit the well-known correlation between the liver’s pathological and mechanical properties through measurements of the Young’s elastic modulus; however, little work has been carried out to examine the effect that fatty deposits may have on the TE measurement accuracy. An investigation was carried out on the effects on the measurement accuracy of a transient elastography ultrasound system, the Fibroscan®, caused by overlaying fat layers of varying thickness on healthy liver-mimicking phantoms, simulating in vivo conditions for obese patients. Furthermore, a steatosis effect similar to that in non-alcoholic fatty …

Nonlinear Optical Properties Of Carbon Nanotube Hybrids In Polymer Dispersions, Jun Wang, Kang-Shyang Liao, Daniel Früchtl, Ying Tian, Aisling Gilchrist , T, Nigel Alley, Enrico Andreoli, Brad Aitchison, Albert Nasibulin, Hugh Byrne, Esko I. Kauppinen, Long Zhang, Werner Blau, Seamus Curran

Articles

A series of double-walled carbon nanotubes (DWNTs) and multi-walled nanotubes (MWNTs) functionalized with selected organic chromophores, fluorescein 5(6)-isothiocyanate (FITC), rhodamine B isothiocyanate (RITC) and fullerene (C₆₀) were synthesized by covalently linking these electron-donor groups to the metallic nanotubes. These versatile carbon nanotube composites show remarkable nonlinear optical (NLO) performance, due to a merged effect of the complementary NLO characteristics of the moieties of the composites. The hybrids were characterized by UV-Vis spectroscopy and Raman spectroscopy. Evidence suggests charge transfer species are formed between the chromophores and the nanotubes. The optical limiting performance of the DWNT, MWNT hybrids and …

Abstract Criteria For Multiple Solutions To Nonlinear Coupled Equations Involving Magnetic Schrodinger Operators, Mattias Enstedt, Michael Melgaard

Articles

We consider a system of nonlinear coupled equations involving magnetic Schrodinger

operators and general potentials. We provide a criteria for the existence of multiple

solutions to these equations. As special cases we get the classical results on

existence of innitely many distinct solutions within Hartree and Hartree-Fock

theory of atoms and molecules subject to an external magnetic fields. We also

extend recent results within this theory, including Coulomb system with a constant

magnetic field, a decreasing magnetic field and a "physically measurable" magnetic field.

Who Do Work Placements As Part Of An Undergraduate Degree Programme Benefit?, Jacinta E. Browne, David O'Brien, John Dorna

Other Resources

No abstract provided.

Characterization And Electrochromic Properties Of Poly(2,3,5,6-Tetrafluoroaniline): Progress Towards A Transparent Conducting Polymer, Lavinia Astratine, Edmond Magner, John Cassidy, Tony Betts

Articles

Electrochromic films of poly(2,3,5,6-tetrafluoroaniline) (PTFA) were formed on ITO substrates from aqueous solutions utilising perchloric acid (HClO₄) as dopant. Electrochemical and spectroscopic characterization of PTFA films was performed in background electrolyte and in solutions with the addition of tetrahydrofuran. When the PTFA film was removed from its growth medium, a significant decrease in the faradaic current was observed. The faradaic response increased on addition of tetrahydrofuran which facilitates ion movement through the polymer matrix. PTFA films deposited on ITO substrate were orange and light orange in the oxidized and reduced forms, respectively. The films were ca. 25 nm …

Analysis Of Human Skin Tissue By Raman Microspectroscopy: Dealing With The Background, Franck Bonnier, Syed Mehmood Ali, Peter Knief, Helen Lambkin, Kathleen Flynn, Vincent Mcdonagh, Claragh Healy, Thomas Lee, Fiona Lyng, Hugh Byrne

Articles

Raman microspectroscopy is widely used for molecular characterisation of tissue samples. Nevertheless, when working in vitro on tissue sections, the presence of a broad background to the spectra remains problematic and its removal requires advanced methods for pre-processing of the data. To date, research efforts have been primarily devoted to development of techniques of statistical analysis to extract the relevant information contained in the spectra. However, few attempts have been made to understand the origin of the background and to improve the protocols used for the collection of Raman spectra that could lead to the reduction or elimination of the …

Industrial And Agricultural Applications Of Solar Heat, Brian Norton

Books/Book chapters

Mankind’s earliest use of solar energy was probably the drying of food crops to aid their preservation. Open sun drying of fruit, vegetables, fish and meats often improved or enhanced particular flavors and textures such that solely because of those attributes many dried products remain in culinary use today, as examples, dried seaweed, sun-dried tomatoes, raisins and dried pistachio nuts. Open sun drying is displaced increasingly by glazed solar dryers that (i) enable equilibrium moisture content to be reached sooner and (ii) avoid losses of the crop to insects and rodents.

A further agricultural application, the greenhouse extended the use …

The Importance Of Human Mental Workload In Web Design, Luca Longo, Fabio Rusconi, Lucia Noce, Stephen Barrett

Conference papers

The focus of this study is the introduction of the construct of Human Mental Workload (HMW) in Web design, aimed at supporting current interaction design practices. An experiment has been conducted using the original Wikipedia and Google web-interfaces, and using two slightly different versions. Three subjective psychological mental workload assessment techniques (NASA-TLX, Workload Profile and SWAT) with a well-established assessments usability tool (SUS) have been adopted. T-tests have been performed to study the statistical significance of the original and modified web-pages, in terms of workload required by typical tasks and perceived usability. Preliminary results show that, in one ideal case, …

An Investigation Into Feature Selection For Oncological Survival Prediction, Dmitry Strunkin, Brian Mac Namee, John D. Kelleher

Conference papers

In machine learning based clinical decision support (CDS) systems the features used to train prediction models are of paramount importance. Strong features will lead to accurate models, whereas as weak features will have the opposite effect. Feature sets can either be designed by domain experts, or automatically extracted for unstructured data that happens to be available from some process other than a CDS system. This paper compares the usefulness of structured expert-designed features to features extracted from unstructured data sources in an oncological survival prediction application scenario.

Identifying And Localizing Intracellular Nanoparticles Using Raman Spectroscopy, Jennifer Dorney, Franck Bonnier, Amaya Garcia, Alan Casey, Gordon Chambers, Hugh Byrne

Articles

Raman microscopy is employed to spectroscopically image biological cells previously exposed to fluorescently labelled polystyrene nanoparticles and, in combination with K-means clustering and Principal Component Analysis (PCA), is demonstrated to be capable of localising the nanoparticles and identifying the subcellular environment based on the molecular spectroscopic signatures. The neutral nanoparticles of 50 nm or 100 nm, as characterised by dynamic light scattering, are shown to be non-toxic to a human lung adenocarcinoma cell-line (A549), according to a range of cytotoxicity assays including Neutral Red, Alamar Blue, Coomassie Blue and (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Confocal fluorescence microscopy identifies intracellular fluorescence due to …

Drift Detection Using Uncertainty Distribution Divergence, Patrick Lindstrom, Brian Mac Namee, Sarah Jane Delany

Conference papers

Concept drift is believed to be prevalent inmost data gathered from naturally occurring processes andthus warrants research by the machine learning community.There are a myriad of approaches to concept drift handlingwhich have been shown to handle concept drift with varyingdegrees of success.

However, most approaches make the keyassumption that the labelled data will be available at nolabelling cost shortly after classification, an assumption whichis often violated. The high labelling cost in many domainsprovides a strong motivation to reduce the number of labelledinstances required to handle concept drift. Explicit detectionapproaches that do not require labelled instances to detectconcept drift show great …