Engineering Commons^™

Look After The Risks, Ask The Right Questions – And Know How To Get Out, Lorcan Sirr

Media

No abstract provided.

Force Measurement And Evaluation For Surgical Cutting Applications: Development Of An Effective Characterisation Testbed, Dean Callaghan

Conference Papers

Sensorized instruments that cater for accurate measurement of the interaction forces (between biological tissue and instrument end-effector) during surgical procedures offer surgeons a greater sense of immersion during minimally invasive robotic surgery (MIRS). There is much ongoing research into force measurement/evaluation involving surgical graspers. However, comparatively little corresponding effort has been expended in the measurement and subsequent evaluation of forces between scissor blades and tissue. This paper presents the design and development of a force/strain measurement test apparatus, which will ultimately serve as an effective sensor characterisation and evaluation platform. Data acquired from the testing platform can be used to …

An Integrated Approach To The Teaching Of Numerical Methods To Engineering Students, Garrett Keane, Michael Carr, Patrick Carroll

Conference papers

In Technological University Dublin, historically, numerical methods were taught to engineering students using a format of traditional mathematics lectures, to a large class group consisting of students from five different engineering disciplines, complemented by small class tutorials. Assessment was by a single, written exam only.

In order to improve the overall effectiveness of the students’ learning experience, it was deemed beneficial to also introduce practical computing classes in which the students would be required to apply the general mathematical methods covered in lectures to discipline-specific examples.

Three different practical computing assignments were devised for the students to undertake, and 20% …

Bs News

Building Services Engineering

No abstract provided.

Changing Training Needs Arising From The Introduction Of Off-Site Construction Techniques, Louis Gunnigan, John Mcdonagh

Conference papers

The objective of this paper is to examine the changes in training needs arising from the increase of off-site construction in the Republic of Ireland. The methodology employed was a case study using a participant observation research technique. For a period of three weeks, the researcher observed the construction of residential housing, constructed using off-site techniques. From the practices observed and from interviews with the operatives on-site, an account of the differences in skills required between those employed in traditional construction and off-site construction was compiled. Each of the different trades involved in traditional construction was addressed and a comprehensive …

Bs News

Building Services Engineering

No abstract provided.

Development Of A Three Dimensional Prolapse Model To Simulate Physiological Haemodynamics In A Stented Coronary Artery, Jonathan Murphy, Fergal Boyle

Conference Papers

Coronary stent implantation can improve blood flow in an artery that has been narrowed by the build up of arterial plaque. However, the haemodynamic effect of stent placement is unclear and may influence arterial restenosis (re-blockage). The degree of tissue prolapse between stent struts may be an important factor in predicting the restenosis rate of a stent due to the haemodynamic influence of the protruding tissue. In this paper a mathematical model has been developed to numerically predict the tissue prolapse for an artery implanted with a coronary stent. The prolapse model has been applied to the Gianturco-Roubin II (GR-II) …

Evolution Of A Computational Domain For Numerical Analysis Of Fluid Mechanical Disturbance Induced By Coronary Stent Deployment, Jonathan Murphy, Fergal Boyle

Conference Papers

No abstract provided.

Lattices In Finite Real Reflection Groups, Colum Watt, Thomas Brady

Articles

For a finite real reflection group, $W$, with Coxeter element $\gamma$ we give a uniform proof that the closed interval, $[I, \gamma]$ forms a lattice in the partial order on $W$ induced by reflection length. The proof involves the construction of a simplicial complex which can be embedded in the type W simplicial generalised associahedron.

A Study Of Sip Based Instant Messaging Focusing On The Effects Of Network Traffic Generated Due To Presence, Finnian Mckeon

Conference Papers

The increasing usage of Instant Messaging(IM) applications worldwide continues to grow year on year. However, larger numbers of users creates problems with greater network traffic, interoperability and proprietary protocol dependence. Network traffic due to presence information being exchanged between users and servers needs to be considered, but is it possible to estimate or measure this traffic? There have been very few studies performed on the impact of presence traffic. The purpose of this research is to implement a SIP/SIMPLE network environment that will allow the evaluation of key metrics such as the latency and throughput of the network under a …

Throughput Enhancement Through Combined Fragmentation And Rate Method In Ieee 802.11b Wlans, Marek Bykowski, Karol Kowalik, Brian Keegan, Mark Davis

Conference papers

IEEE 802.11 allows for fragmentation tuning and rate selection. Their combined usage is referred sometimes to link adaptation. However, the algorithms of link adaptation are beyond the 802.11 standards. In this paper we investigate the benefits arising from proper use of link adaptation. Particularly, we develop a mathematical model describing the fragmented transmission in 802.11b. We examine potential benefits of it over AWGN and fading channels. More significantly we combine fragmentation tuning with bit-rate selection to yield the highest achievable throughput performance for any given channel conditions. Finally, we propose an algorithm that performs the optimal link adaptation.

A Microstrip Printed Dipole Solar Antenna Using Polycrystalline Silicon Solar Cells, S. Shynu, Maria Roo Ons, Giuseppe Ruvio, Max Ammann, Sarah Mccormack, Brian Norton

Conference papers

A novel printed dipole solar antenna design with an integrated balun is proposed for the first time with high efficiency polycrystalline silicon solar cells is presented in this paper. The optimum orientation of the silver DC bus bars of the solar cell is determined in order to achieve best antenna performance. Good solar antenna performance similar to that of ordinary printed dipoles with PEC reflectors is achieved.

Development Of A Knowledge Management Strategy For Academic Staff, Leslie Whyte

Dissertations

We are living in a knowledge society. Knowing what we know and managing it better to know more is considered the key enabler to sustainable economic growth. 70 to 80 percent of economic growth is directly attributed to new or better knowledge. With information communication technologies (ICT) readily facilitating the globalisation of economic activity, the key competitive advantage of this era is the ability to create, use and disseminate knowledge effectively. Although traditionally creators, guardians and disseminators of knowledge, universities and institutions need to also adapt to the challenges the knowledge society can bring and evolve their roles in education, …

Effect Of Carbon Black On The Mechanical Performances Of Magnetorheological Elastomers, Lin Chen

Articles

Several magnetorheological elastomer (MRE) samples, with different weight percentages of carbon black, were fabricated under a constant magnetic field. Their microstructures were observed by using an environmental scanning electron microscope (SEM), and their mechanical performance including magnetorheological (MR) effect, damping ratio and tensile strength were measured with a dynamic mechanical analyzer (DMA) system and an electronic tensile machine. The experimental results demonstrate that carbon black plays a significant role in improving the mechanical performance of MR elastomers. Besides the merits of high MR effect and good tensile strength, the damping ratio of such materials is much reduced. This is expected …

Influence Of Fiber Manufacturing Tolerances On The Spectral Response Of A Bend Loss Based All-Fiber Edge Filter, Pengfei Wang, Gerald Farrell, Yuliya Semenova, Ginu Rajan

Articles

It is shown that manufacturing tolerances of the fiber parameters bend radius and NA significantly influence the fiber bend loss performance and spectral response of a fiber-based edge filter. A theoretical model, validated by experimental results, is used to determine the changes in key spectral parameters for an edge filter, resulting from changes within their manufacturing tolerance range, for both the bend radius and NA. Finally is shown that bend-radius tuning during fabrication of such filters is a means of mitigating the effect of manufacturing variations.

Quarter-Wave Metal Plate Solar Antenna, S. Shynu, Max Ammann, Brian Norton

Articles

A novel design of a quarter-wave shorted trapezoidal metal plate solar antenna using high efficiency polycrystalline silicon solar cells is presented. Using the DC conductive parts of the cell as RF antenna elements as well as choosing the radiating element to be a small base trapezoid, better coupling between the feed and shorting plates is ensured and 40.3% size reduction compared to a conventional shorted quarter-wave patch is obtained. The trapezoidal radiating element covers merely 2.7% of the total available illumination area of the solar cell, leaving its efficiency essentially unaffected. The proposed design strategy has been verified by an …

Group Velocity Dispersion Reduction In Fibre-Based Slow-Light Systems Via Stimulated Brillouin Scattering, Ronny Henker, A. Wiatrek, K. U. Lauterbach, Max Ammann, Andreas Schwarzbacher, Thomas Schneider

Articles

Presented are theoretical investigations and simulations of a reduction of the group velocity dispersion (GVD) in slow-light systems by an optimisation of the gain spectrum of the stimulated Brillouin scattering (SBS). A comparison between a natural Brillouin gain spectrum and a broadened Brillouin gain spectrum with and without two additional losses at its wings is demonstrated. The focus of the theoretical examination was set on the superposition of a gain and two losses with an equal magnitude. Therefore, a low GVD and a high group index change could be achieved and hence, a small pulse distortion and a high time …

A Synthesised Knowledge Mapping Framework To Embed A Km Strategy Using Topic Maps And Wikis: The Tao Of Wiki, Colman A.J. Mcmahon

Dissertations

Just getting started with knowledge management can be difficult enough for many organisations, however the real challenge is actually how to embed the new practices. The expression "Success is a journey, not a destination" is particularly apt for KM. This research presents findings from stakeholder analyses carried out in an Irish government agency. The agency has been on its KM journey for nearly four years and has attempted to implement a comprehensive and full-scale strategy. The findings indicate that KM practices have not yet become fully embedded in the organisation. This research uncovers some of the reasons why not. In …

Assessing The Impact Of Organisational Culture When Introducing Web.2.0 Technologies Into A Non-Profit Organisation For Knowledge Managment, Heather Madden

Dissertations

Some of the key challenges that any organisation faces today are those of knowledge sharing and collaboration. This research investigates knowledge sharing in existing communities of practice in a non-profit organisation and the challenges that are faced by attempting to facilitate online interactions for these communities. Organisation culture can either incentivise or impede this process and this research will describe how people and culture are two of the most important factors when considering a knowledge management initiative. Given that the impact of culture is such a key issue, a number of organisations are interviewed and evaluated to compare and contrast …

Communication Of Medical Information Using Agents, John Mcgrory, Jane Grimson, Frank Clarke, Peter Gaffney

Conference Papers

Agents are self-contained software entities which act faithfully and autonomously on behalf of a body of knowledge. They can operate in a standalone capacity, or as part of a social group collaborating and

coordinating activities with other software agents. To access their knowledge, agents are interfaced with

using message passing communication. The principle behind medical communications is to provide a means

for exchanging information and knowledge from one computerised location to another, whilst preserving its

true meaning and understanding between the listener and sender. Agent communication is similar to medical

communications, but must provide an additional framework element to allow …

Extended Nonnegative Tensor Factorisation Models For Musical Sound Source Separation, Derry Fitzgerald, Matt Cranitch, Eugene Coyle

Articles

Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound souce separation of pitched musical instruments. However, in practice, existing alogorithsm require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Futher, these additional constraints allow the addition of a source filter model to the …

Musical Source Separation Using Generalised Non-Negative Tensor Factorisation Models, Eugene Coyle, Derry Fitzgerald, Matt Cranitch

Conference papers

A shift-invariant non-negative tensor factorisation algorithm for musical source separation is proposed which generalises previous work by allowing each source to have its own parameters rather a fixed set of parameters for all sources. This allows independent control of the number of allowable notes, number of harmonics and shifts in time for each source. This increased flexibility allows the incorporation of further information about the sources and results in improved separation and resynthesis of the separated sources.

Time And Pitch Scale Modification: A Real-Time Framework And Tutorial, Dan Barry, David Dorran, Eugene Coyle

Conference papers

A framework is presented which is designed to address the issues related to the real-time implementation of time-scale and pitch scale modification algorithms. This framework can be used as the basis for the developments of applications which allow for a seamless real-time transition between continually varying time scale and pitch-scale parameters which arise as a result of manual or automatic intervention.

The Annotation Of Traditional Irish Dance Music Using Matt2 And Tansey, Bryan Duggan, Brendan O'Shea, Mikel Gainza, Padraig Cunningham

Conference papers

Current estimates put the canon of traditional Irish dance tunes at least 7,000 compositions. Given this diversity, a common problem faced by musicians and ethnomusicologists is identifying tunes from recordings. This is evident even in the number of commercial recordings whose title is gan aimn (without name). This work attempts to solve this problem by developing a Content Based Music Information Retrieval (CBMIR) System adapted to the characteristics of traditional Irish music. A system is presented called MATT2 (Machine Annotation of Traditional Tunes) whose primary goal is to annotate recordings of traditional Irish dance music with useful meta-data including tune …

Linear Prediction: The Problem, Its Solution And Application To Speech, Alan O'Cinneide, David Dorran, Mikel Gainza

Conference papers

Linear prediction is a signal processing technique that is used extensively in the analysis of speech signals and, as it is so heavily referred to in speech processing literature, a certain level of familiarity with the topic is typically required by all speech processing engineers. This paper aims to provide a well-rounded introduction to linear prediction, and so doing, facilitate the understanding of the technique. Linear prediction and its mathematical derivation will be described, with a specific focus on applying the technique to speech signals. It is noted, however, that although progress in linear prediction has been driven primarily by …

Metadata Visualisation Techniques For Emotional Speech Corpora, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

Our research in emotional speech analysis has led to the construction of dedicated high quality, online corpora of natural emotional speech assets. Once obtained, the annotation and analysis of these assets was necessary in order to develop a database of both analysis data and metadata relating to each speech act. With annotation complete, the means by which this data may be presented to the user online for analysis, retrieval and organization is the current focus of our investigations. Building on an initial web interface developed in Ruby on Rails, we are now working towards a visually driven GUI built on …

Development Of A Construction Sub-Sector Embodied Energy Hybrid Analysis, Adolf Acquaye, Aidan P. Duffy, Biswajit Basu

Working papers

Embodied energy analysis is used to evaluate the total energy consumed by any product during all the stages leading up to its manufacture and delivery and can also be used to determine the energy-related environmental impacts such as CO2 emissions of buildings and other built infrastructure. In the wake of increase global awareness on climate change and the strong link between global warming and CO2 emissions, the role of new and improved analytical models to evaluate the energy embodied in products and its associated environmental impacts therefore takes an important role in environmental research studies. The development of a new …

Experimental And Numerical Investigation Of Wire Waveguides For Therapeutic Ultrasound Angioplasty, Declan Noone (Thesis)

Other resources

Therapeutic ultrasound angioplasty is an emerging minimally invasive cardiovascular procedure for disrupting atherosclerotic lesions using small diameter wire waveguides. The lesions are damaged through a combination of direct ablation, pressure waves, cavitation and acoustic streaming caused by distal-tip displacements at ultrasonic frequencies. Numerical and experimental methods are used to investigate the outputs of the wire waveguides during ultrasonic activation. A commercially available generator and acoustic horn are used in combination with Nickel-Titanium (NiTi) wire waveguides in this study. A laser sensor is used to measure the frequency and amplitude output of the distal tip of the wire waveguide, and this …

Group Delay Performance Of Ultra Wideband Monopole Antennas For Communication Applications, Patrick Mcevoy, Matthias John, Sergio Curto, Max Ammann

Conference papers

While limited in dimensions, the shape of small ultra wideband (UWB) antennas can significantly impact on the required gain pattern stablity and the inherent impulse spreading throughout the bandwidth. The comparative gain performance of a square monopole and two Bezier-spline shaped monopoles (optimised for low insertion losses on small groundplanes) as portable UWB device antennas solutions are reported. By measuring the transmission group delay for the three geometries in paired combinations, the time-domain spreading due to each individual antenna is solved numerically with a system of equations.

Uwb Vivaldi Antenna Based On A Spline Geometry With Frequency Band-Notch, Matthias John, Max Ammann, Patrick Mcevoy

Conference papers

A printed UWB Vivaldi antenna is presented in this paper. Its geometry is based on a novel spline shape and optimised by an efficient global optimisation algorithm. A U-shaped slot is introduced into the geometry to notch out the 5.1 GHz to 5.8 GHz WLAN band. This can be used to mitigate interference between WLAN and UWB systems.