Engineering Commons^™

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 …

A Teaching Practice Review Of The Use Of Multiple-Choice Questions For Formative And Summative Assessment Of Student Work On Advanced Undergraduate And Postgraduate Modules In Engineering, Aidan O'Dwyer

Articles

This paper reflects on, reports on and evaluates the use of multiple-choice questions, in both formative and summative assessment modes, on control engineering modules taken by advanced undergraduate and postgraduate engineering students, over four academic years. The material covered by the modules is analytical in nature. The rationale for examining the assessment strategy was the poor performance by students in a closed book traditional terminal examination on one of the advanced undergraduate modules over some years. The change in assessment strategy has improved student learning, as measured by assessment data; student feedback on the assessment methods is broadly positive. The …

Properties Of Non-Tilted Bent-Core Orthogonal Smectic Liquid Crystal, S. Sreenilayam, M. Nagaraj, Yuri Panarin, J. K. Vij, A. Lehmann, C. Tschierske

Articles

We present the properties of different achiral orthogonal polar smectic phases observed in a homologous series of bent-core molecular compounds. The macroscopically uniaxial SmAPR phase transforms to biaxial state by the application of higher electric fields and biaxial SmAPA phase undergoes biaxial-uniaxial-biaxial texture transformation with increasing electric fields,i.e.,initial antiferroelectric structure transforms into ferroelectric state under higher electric fields and it shows three different optically distinguishable states. The SmAPAR phase shows an entirely different response compared to other polar smectic phases under study. The dielectric measurements in the SmAPAR phase is the evidence of antiferroelectric behavior of uniaxial state. The polarizing …

Speech Intelligibility Prediction Using A Neurogram Similarity Index Measure, Andrew Hines, Naomi Harte

Articles

Performance Intensity functions can be used to provide additional information over measurement of speech reception threshold and maximum phoneme recognition by plotting a test subject's recognition probability over a range of sound intensities. A computational model of the auditory periphery was used to replace the human subject and develop a methodology that simulates a real listener test. The newly developed NSIM is used to evaluate the model outputs in response to Consonant-Vowel-Consonant (CVC) word lists and produce phoneme discrimination scores.

A Generalized Version Of An Ivantsov-Based Dendrite Growth Model Incorporating A Facility For Solute Measurement Ahead Of The Tip, Shaun Mcfadden, David Browne

Articles

Extensions to the Ivantsov dendrite growth model are presented, which allow for increased solute levels in the field ahead of the dendrite tip. This model is intended for use with video-microscopy experimental results taken from synchrotron radiography sources. Ideally, the composition and composition gradient at the solid-liquid interface would be measured. However, due to the spatial resolution limitations, it is difficult to accurately measure the composition at the interface. This paper sets out an extended description of the theory where measurements ahead of the tip determine the operating conditions at the tip. This extended model of dendritic growth may be …

Analysis Of Wind Velocity Signals For Estimating The Wave Power Density Of Ireland's Coastal Resource, Jonathan Blackledge, Eugene Dermot Coyle Professor, Derek Kearney, Ronan Mcguirk

Articles

The aim of this paper is to report on a possible correlation between the Lévy index for the wind velocity and the mean Energy Density of sea surface waves in the same location. The result is based on data obtained from six buoys located around the coast of Ireland and maintained by the Marine Institute of Ireland. These buoys provide signals on the wind velocity, wave height and wave period as well as other data on an hourly interval. Using this data, we consider the relationship between a stochastic model for the time variations in wave height that, in turn, …

Computation Of The Stochastic Volatility And Levy Index Using The Kolmogorov-Feller Equation With Applications To Carbon Price Data Analysis, Jonathan Blackledge, Marc Lamphiere, Afshin Panahi

Articles

We derive new algorithms for computing time variations in the Stochastic Volatility and the L´evy index using a standard financial price model and a Green’s function solution to the Kolmogorov-Feller equation. A principal condition upon which the algorithms are based is the Phase Only Condition which allows the Power Spectral Density Function of a financial time series (specifically the log price differences) to be taken to be a constant. The paper is composed of four component parts: (i) the Stochastic Volatility is derived and studied numerically; (ii) the Kolmogorov-Feller equation is studied and solved to provide a model for the …

Evaluation Of A Prototype Desktop Virtual Reality Model Developed To Enhance Electrical Safety And Design In The Built Environment, Martin Barrett, Jonathan Blackledge

Articles

The use of Desktop Virtual Reality (VR) systems for enhancing electrical safety and engineering design is a novel prospect for both practicing and student electrical services engineers. This innovative approach, which can be readily accessed via the World Wide Web, constitutes a marked shift in conventional learning and design techniques to a more immersive, interactive and intuitive working and learning environment. This paper initially identifies the unique characteristics of desktop web based VR technologies and highlights the educational affordances offered by working in such an environment. Subsequently, using a prototype model titled ‘Virtual Electrical Services’, a case study is carried …

Non-Gaussian Anisotropic Diffusion Processing For Medical Imagining Using The Osirix Dicom Viewer, Jonathan Blackledge, Matthew Blackledge, Jane Courtney

Articles

Medical imaging is a fertile area for computer graphics, image processing and real time visualization. In this paper we present a method for reducing noise in CT (Computed Tomography) and MR (Magnetic Resonance) images that (in addition to other noise sources) is characteristic of the numerical procedures required to construct the images, namely, the (inverse) Radon Transform. In both cases, MR imaging in particular, an additional noise source is due to the process of diffusion thereby predicating use of the Anisotropic Diffusion method for noise suppression. This method is based on a diffusion model for noise generation where the Diffusivity …

Energy Commodities Trading Using A Phase Signal Derived From The Levy Index Of Price And Volatility, Jonathan Blackledge, Derek Kearney, Claire Farrell, Grace Kearney

Articles

Energy traders need to decide what markets and commodities to trade in, when to open and close trades and how to maximize profits. In this paper we consider an approach for analyzing energy commodity price data based on the Lévy index in order to develop a new short-term predictive trend indicator for the price. This is achieved by computing the unwrapped phase signal generated from the Lévy index of both the Stochastic Volatility and price and is evaluated using data from the Irish Energy Market, namely, time series for the price of Electricity, Gas and Oil. The initial results show …

Wind Resource In The Urban Environment, Jonathan Blackledge, Eugene Coyle, Derek Kearney, Eamonn Murphy, Maria-Jose Rivas Duartes

Articles

The World Meteorological Organization (WMO) Commission for Instruments and Methods of Observation recognized the need to include in the 1996 WMO Guide to Instruments and Methods of Observation, WMO No. 8 a new chapter on Urban Observations (Oke 2006). There is an increasing demand for meteorological data to support building and urban design, energy conservation, micro -wind turbine installation, air quality, pollution control, insurance, wind engineering, etc. Over the last six years instrumentation has been installed at the Dublin Ins titute of Technology (DIT) in two separate locations to monitor the wind. Research has shown that the wind resource will …

Analysis Of Wind Velocity And The Quantification Of Wind Turbulence In Rural And Urban Environments Using The Levy Index And Fractal Dimension, Jonathan Blackledge, Eugene Coyle, Niall Mccoy, Derek Kearney, Keith Sunderland, Thomas Woolmington

Articles

This paper is concerned with a quantitative and comparative analysis of wind velocities in urban and rural environments. It is undertaken to provide a route to the classification of wind energy in a rural and urban setting. This is a common problem and the basis of a significant focus of research into wind energy. In this paper, we use a non-Gaussian statistical model to undertake this task, and, through a further modification of the data analysis algorithms used, extend the model to study the effect of wind turbulence, thereby introducing a new metric for this effect that is arguably superior …

Upqc For Power Quality Improvement In Dg Integrated Smart Grid Network: A Review, Shafiuzzaman Khadem, Malabika Basu, Michael Conlon

Articles

Quality of power supply has become an important issue with the increasing demand of Distributed Generation (DG) systems either connected to the grid through some power electronics grid-tie inverters or to work in isolated (microgrid) mode towards the development of a smart grid network. In this paper a technical review of Integration of Unified Power Quality Conditioner (UPQC) in Distributed Generation Network has been presented. Though the primary task of UPQC is to minimize the grid voltage and load current disturbance along with the reactive and harmonic power compensation, additional functionalities like compensation of voltage interruption and active power transfer …

Structure And Polymorphism Of Biaxial Bent-Core Smectic Liquid Crystal, S. Sreenilayam, M. Nagaraj, Yuri Panarin, J. K. Vij, A. Lehmann, C. Tschierske

Articles

The mesomorphic properties of a homologous series of achiral bent-core compounds are studied by polarizing optical microscopy, electro-optics and polarization measurements. Induction of a new orthogonal smectic phases with the increase of alkyl side chain length was observed. One of the compounds exhibits a unique phase transition between four non-tilted smectic phases (SmAPA–SmAPAR-SmAPR-SmA). The uniaxial but antiferroelectric nature of SmAPAR phase was confirmed by POM, current response, the 2nd harmonic electro-optic response and polarization measurements. The structure of SmAPAR phase was studied theoretically by Next-Nearest-Neighbor model and was identified as SmAPα.

Developments In Performance Monitoring Of Concrete Exposed To Extreme Environments., W. J. Mccarter, T. M. Chrisp, G. Starrs, A. Adamson, E. Owens, P. A. M. Basheer, S. V. Nanukuttan, S. Srinivasan, Niall Holmes

Articles

The performance of the surface zone of concrete is acknowledged as a major factor governing the rate of deterioration of reinforced concrete structures because it provides the only barrier to the ingress of water containing dissolved ionic species such as chlorides, which ultimately initiate corrosion of the reinforcement. In situ monitoring of cover-zone concrete is therefore critical in attempting to make realistic predictions as to the in-service performance of the structure. To this end, this paper presents developments in a remote interrogation system to allow for continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is made …

Clinical Coverage Of An Archetype Repository Over Snomed-Ct., Sheng Yu, Damon Berry, Jesus Bisbal

Articles

Clinical archetypes provide a means for health professionals to design what should be communicated as part of an Electronic Health Record (EHR). An ever-growing number of archetype definitions follow this health information modelling approach, and this international archetype resource will eventually cover a large number of clinical concepts. On the other hand, clinical terminology systems that can be referenced by archetypes also have a wide coverage over many types of health-care information.

No existing work measures the clinical content coverage of archetypes using terminology systems as a metric. Archetype authors require guidance to identify under-covered clinical areas that may need …

Nanozeolites Doped Photopolymer Layers With Reduced Shrinkage, Mohesh Moothanchery, Izabela Naydenova, Svetlana Mintova, Vincent Toal

Articles

An acrylamide based photopolymer doped with pure silica MFI-type zeolite (silicalite-1) nanoparticles has been characterized for holographic recording purposes. The concentrations of the silicalite-1 nanoparticles in the photopolymer layers were 1, 2.5, 5 and 7.5 wt.%. The inclusion of silicalite-1 nanoparticle in the photopolymer has resulted in an increase of the diffraction efficiency by up to 40%, and decrease of the shrinkage from 1.32% to 0.57%. The best results were obtained in layers doped with 5 wt.% silicalite-1 nanoparticles.

Physicochemical And Microbiological Quality Of Water From A Pilot Domestic Rainwater Harvesting Facility In Ireland., Sean O'Hogain, Liam Mccarton, Niamh Mcintyre, Jenny Pender, Anna Reid

Articles

DTC Research Group, Dublin Institute of Technology personnel were commissioned in 2005 by the Department of Environment, Heritage and Local Government in Ireland to assess the feasibility of utilising harvested rainwater to replace treated mains water, for non-potable uses. A pilot project was set up. The project involved the design, installation, commissioning and monitoring of rainwater harvesting facilities in a rural housing development. A monitoring program was carried out to examine the physico-chemical and microbiological quality of the harvested rainwater. Harvested rainwater was sampled monthly and tested. Analysis of the harvested rainwater quality showed a consistently high quality of raw …

Light Coupling Between A Singlemode-Multimode-Singlemode (Sms) Fiber Structure And A Long Period Fiber Gating, Qiang Wu, Yuliya Semenova, Youqiao Ma, Pengfei Wang, Tuan Gao, Long Jin, Gerald Farrell

Articles

We propose a novel optical coupling technique based on evanescent field coupling between a singlemode-multimode-singlemode (SMS) fiber structure and a long period fiber grating (LPFG). By parallel placement of the two fiber sections in close proximity to each other, the excited multi-cladding modes from the SMS fiber section can be selectively coupled to the guided mode in the LPFG, and vice versa. A theoretical analysis based for such a structure is undertaken and the simulated results are verified by experiments demonstrating a maximum coupling efficiency of up to 1.66% (which could be improved to 27.5% in theory) over a broadband …

Going Green, Dermot Kehily

Articles

No abstract provided.

Dc Pulsed Atmospheric Pressure Plasma Jet Image Information, Denis P. Dowling, F T. O'Neill, Vladimir Milosavljevic, Victor J. Law

Articles

This paper presents optical imaging and optical emission spectroscopy (OES) data of an atmospheric-pressure plasma jet. It is shown how the visual information and OES information of the air discharge are related as the blown arc extends from the nozzle (2-4 mm) with a molecular nitrogen rotational temperature on the order of 1700 K and the flowing afterglow beyond this region is dominated by the cooler (300-K) NO-O chemiluminescent reaction that produces NO₂ species.

Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern

Articles

This technical note describes diagrams of friction factor for pipe flow that have been prepared using, mainly, the equations that Lewis Moody used to prepare his famous diagram in 1944. The preparation of the new diagrams was prompted by the need for vector graphics versions that could be used for teaching purposes and that could be distributed freely to students and others under a Creative Commons Attribution-Share-Alike license. Using a structure very similar to that of Moody's diagram, variants with the Darcy friction factor and the Fanning friction factor have been prepared. In addition, variants have been prepared that include …

Domestic Application Of Micro Wind Turbines In Ireland: Investigation Of Their Economic Viability, Zhe Li, Fergal Boyle, Anthony Reynolds

Articles

Electricity generation from renewable sources of energy will be a key part in the development of future strategies for many countries globally. This renewable electricity generation will be hugely important for Ireland, due to its lack of fossil fuel resources. The extremely good wind resource available provides Ireland with the opportunity of generating vast amount of electricity from wind energy. Large-scale wind electricity generation reached 1264 MW installed capacity by January 2010 in Ireland. However, micro scale wind electricity generation has not been very popular in Ireland to-date. The unclear economics of micro wind turbines, under Irish conditions, is considered …

Numerical Study Of An Ion-Exchanged Glass Waveguide Using Both Two-Dimensional And Three-Dimensional Models, Pengfei Wang, Yuliya Semenova, Jie Zheng, Qiang Wu, Agus Hatta, Gerald Farrell

Articles

A numerical study is carried out to compare the two-dimensional (2-D) case and three-dimensional (3-D) case for the modelling of an ion-exchanged glass waveguide. It is shown that different waveguide widths on the photomask correspond to different ion concentration distributions after an annealing process. A numerical example is presented of two waveguide sections with different widths indicates that due to the abrupt change of the waveguide width, a 3-D theoretical model is required for an accurate prediction of the parameters of ion-exchanged glass waveguides. The good agreement between the modelled and measured results proves that the developed 3-D numerical model …

Rational Efficiency Of A Heat Exchanger, Jim Mcgovern, Brian P. Smyth

Articles

The authors propose a new and unique definition for the rational efficiency of a heat exchanger. This new rational efficiency is defined in terms of its sub-rational efficiencies: a heat transfer rational efficiency and a friction rational efficiency for each of the fluid systems comprising the heat exchanger. The heat transfer rational efficiency is based on the definition of a mean temperature for the heat source and a mean temperature for the heat sink and reflects the exergy supplied and the exergy received, due to heat transfer only. The friction rational efficiency for each fluid system of the heat exchanger …

Productivity Evaluation Of Self-Adaptive Software Model Driven Architecture, Basel Magableh

Articles

Anticipating context changes using a model-based approach requires a formal procedure for analysing and modelling context-dependent functionality and stable description of the architecture which supports dynamic decision-making and architecture evolution. This article demonstrates the capabilities of the context-oriented component-based application-model-driven architecture (COCA-MDA) to support the development of self- adaptive applications; the authors describe a state-of-the-art case study and evaluate the development effort involved in adopting the COCA-MDA in constructing the application. An intensive analysis of the applica- tion requirements simplified the process of modelling the application’s behavioural model; therefore, instead of modelling several variation models, the developers modelled an extra-functionality …

A Novel High Sensitive Optical Fiber Microphone Based On A Singlemode-Multimode-Singlemode Structure, An Sun, Yuliya Semenova, Qiang Wu, Agus Hatta, Gerald Farrell

Articles

In this paper, a novel multimode interference based optical fiber microphone by employing singlemode-multimode-singlemode (SMS) structure is presented. The acoustic vibration is measured by detecting the transmission loss of the SMS structure that attached to a thick aluminum membrane. Experiments are carried on to test the performance of SMS structured fiber microphone and the experimental results show that the SMS fiber sensor can effectively detect the acoustic signal within the audio range of 20 KHz. It also exhibits a high sensitivity and human voice can also be picked up effectively within the distance of 2 m.

Self-Adaptive Application For Indoor Wayfinding For Individuals With Cognitive Impairments, Basel Magableh, Stephen Barrett

Articles

This article focuses on describing a Model Driven Archi- tecture (COCA-MDA) approach that facilitates the develop- ment of self-adaptive application for indoor wayfinding for individuals with cognitive impairments. COCA-MDA pro- vides the following benefits: 1) It enables the architecture to anticipate several behavioural variations based on the context and the specific needs of the individuals with cog- nitive impairments. 2) It enables the application to proac- tively anticipate or reactively address unforeseen changes through support by a dynamic-decision making and policy framework. The policy framework is based on a stable de- scription of software models and proprieties. 3) It can …

Model-Driven Productivity Evaluation For Self-Adaptive Context-Oriented Software Development, Basel Magableh, Stephen Barrett

Articles

Anticipating context changes using a model-based approach requires a formal procedure for analysing and mod- elling their context-dependent functionality, and a stable descrip- tion of the architecture which supports dynamic decision-making and architecture evolution. This article demonstrates the capabil- ities of the context-oriented component-based application-model- driven architecture (COCA-MDA) to support the development of self-adaptive applications; we describe a state-of-the-art case study and evaluate the development effort involved in adopting the COCA-MDA in constructing the application. An intensive analysis of the application requirements simplified the process of modelling the application’s behavioural model; therefore, instead of modelling several variation models, the developers …

A Microfiber Cavity With Minimal-Volume Confinement, Ming Ding, Pengfei Wang, Timothy Lee, Gilberto Brambilla

Articles

We demonstrate a type of microcavity with minimal-volume confinement using a high-contrast phase-shifted Bragg grating in a microfiber. While waveguiding by the air-silica boundary provides a diffraction-limited two-dimensional confinement, the grating introduces the third degree of confinement. Theoretical simulations verified the microfiber cavity confinement while the experimental demonstration, carried out in samples nanostructured by focused ion beam, showed a good agreement with theoretical predictions. This cavity can be used for a variety of applications ranging from sensing to quantum dynamic experiments.