Engineering Commons^™

The Human Eye Position Control System In A Rehabilitation Setting, Yvonne Nolan, Ted Burke, C. Boylan, Annraoi De Paor

Articles

Our work at Ireland’s National Rehabilitation Hospital involves designing communication systems for people suffering from profound physical disabilities. One such system uses the electro-oculogram, which is an (x,y) system of voltages picked up by pairs of electrodes placed, respectively, above and below and on either side of the eyes. The eyeball has a dc polarisation between cornea and back, arising from the photoreceptor rods and cones in the retina. As the eye rotates, the varying voltages projected onto the electrodes drive a cursor over a mimic keyboard on a computer screen. Symbols are selected with a switching action derived, for …

A Case-Based Technique For Tracking Concept Drift In Spam Filtering, Sarah Jane Delany, Padraig Cunningham, Alexey Tsymbal, Lorcan Coyle

Articles

Spam filtering is a particularly challenging machine learning task as the data distribution and concept being learned changes over time. It exhibits a particularly awkward form of concept drift as the change is driven by spammers wishing to circumvent spam filters. In this paper we show that lazy learning techniques are appropriate for such dynamically changing contexts. We present a case-based system for spam filtering that can learn dynamically. We evaluate its performance as the case-base is updated with new cases. We also explore the benefit of periodically redoing the feature selection process to bring new features into play. Our …

Friction And Adhesion In Rigid Surface Indentation Of Nitrile Rubber, Stephen Jerrams

Articles

When a rigid body in the form of a plane strain indentor is forced into an elastomer, the asperities on the surface of the indentor are filled by the softer material. As depth of ingress increases, the rubber displaced into the indentor asperities exhibits stick-slip behaviour. The rubber adheres to the rigid body and if the depth of ingress is held at a maximum, the level of adhesion remains constant despite short-term load relaxation occurring in the rubber.

This text describes the influence of a range of factors on indentation forces and adhesion in rigid indentation of hydrogenated nitrile rubbers. …

Water Conservation And Resuse Strategy For Ireland, Liam Mccarton, Sean O'Hogain

Articles

The traditional approach to meeting increased demand is to augment supply. However, mobilising new resources involves ever higher costs. Increasing water efficiency by reducing the amount of water required to accomplish a given task can significantly contribute towards balancing supply and demand. The water saved as a result of PCC reduction can be used to augment existing supplies. This can be the least cost option, particularly when the environmental and social costs of developing new resources are included in the analysis. Allied to this is the concept of sustainability, which can be defined as ‘development that meets the needs of …

Optimization Of Impedance Bandwidth For The Printed Rectangular Monopole Antenna, Matthias John, Max Ammann

Articles

This paper describes a printed rectangular-plate monopole fed by microstrip line. The effect of varying the plate width, feed-gap height, and feedline width on the impedance bandwidth is examined. It is shown that for a fixed ground-plane size, that optimization of these parameters can yield an impedance bandwidth ratio of 4.3:1, without using any broadbanding techniques.

Optimum Design Of The Printed Strip Monopole, Max Ammann, Matthias John

Articles

A monopole antenna, printed on low-cost laminate and fed by a microstrip line, is examined. These types of antennas are becoming popular in view of their broad bandwidth and low-profile structure, enabling easy integration as a terminal antenna. The move away from a classical ground plane (with normal radiator) is one of the attractive features of these antennas, but the full effects of the radiator and ground plane being on opposite sides of the same laminate are often not investigated. The effect of these ground planes on the impedance bandwidth and radiation pattern is investigated experimentally and numerically.

Study Of Transmission Response Of Edge Filters Employed In Wavelength Measurements, Qian Wang, Gerald Farrell, Thomas Freir

Articles

The ratiometric wavelength-measurement system is modeled and an optimal design of transmission response of the employed edge filter is demonstrated in the context of a limited signal-to-noise ratio of the signal source. The corresponding experimental investigation is presented. The impact of the limited signal-to-noise ratio of the signal source on determining the optimal transmission response of edge filters for a wavelength-measurement application is shown theoretically and experimentally.

Theoretical And Experimental Investigations Of Macro-Bend Losses For Standard Single Mode Fibers, Qian Wang, Gerald Farrell, Thomas Feir

Articles

Modeling of macro-bend losses for single mode fibers with multiple cladding or coating layers is presented. Macro-bend losses for standard single mode fibers (SMF28) are investigated theoretically and experimentally, showing that the inner primary coating layer of SMF28 has a significant impact on the bend losses and most of the radiation field is absorbed in the inner primary coating layer of SMF28. The agreement between theoretical calculations and experimental measurements suggests that the so-called elastooptical correction in modeling is not required for SMF28.

Use Of Advanced Synthesis Tools In Teaching Vlsi Design, Kevin Berwick, Dominic Nardone

Articles

No abstract provided.

The Effect Of The Internal Field On The Ir Absorption Spectra Of Small Particles In Case Of 3d, 2d And 1d Size Confinement, Igor I. Shaganov, Tatiana S. Perova, R. Alan Moore, Kevin Berwick

Articles

The spectral properties of composite materials based on small particles under 1D, 2D, and 3D size confinement are described using a combination of dispersive internal field and effective media theory approaches. Calculations performed for a number of crystalline materials have shown that the peak position and intensity of the vibrational band of the material under conditions of 1D, 2D, and 3D size confinement are changed, whereas the bandwidth of the band remains the same. In the case of 3D confinement, the peak position of the spectrum of isolated “mesoparticles” ( ) appears to be very close to the intrinsic frequency …

Adaptive Voip Playout Scheduling: Assessing User Satisfaction, Miroslaw Narbutt, Andrew Kelly, Liam Murphy, Philip Perry

Articles

Delay and packet loss dramatically affect the quality of a voice-over-IP (VoIP) call and depend on the playout buffer scheme implemented at the receiver. The choice of playout algorithm can’t be based on statistical metrics without considering the perceived end-to-end conversational speech quality. The authors present a method for evaluating various playout algorithms that extends the Emodel concept by estimating user satisfaction from time-varying transmission impairments. This article evaluates several playout algorithms and shows a correspondence between their results and those obtained via statistical loss and delay metrics.

Current And Future Applications Of Surface Engineering, David Kennedy, Yueqiang Xue, Emilia Mihaylova

Articles

No abstract provided.

Printed Triband Terminal Antenna, Matthias John, Max Ammann, R. Farrell

Articles

This paper presents a printed triple-band multibranch monopole for use in modern wireless systems. The antenna is designed to operate in three bands which cover virtually all wireless channels. Parameters of the antenna geometry are varied and the effects of these variations on the impedance bandwidth are shown.

An Explicit Mapping Between The Frequency Domain And The Time Domain Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

Explicit expressions are presented that describe the input-output behaviour of a nonlinear system in both the frequency and the time domain. The expressions are based on a set of coefficients that do not depend on the input to the system and are universal for a given system. The anharmonic oscillator is chosen as an example and is discussed for different choices of its physical parameters. It is shown that the typical approach for the determination of the Volterra Series representation is not valid for the important case when the nonlinear system exhibits oscillatory behaviour and the input has a pole …

Holographic Patterning Of Acrylamide-Based Photopolymer Surface, Izabela Naydenova, Emilia Mihaylova, Suzanne Martin, Vincent Toal

Articles

The patterning of an acrylamide-based photopolymer surface by holographic recording is studied. The patterns are induced by light alone and no post-processing is required. Periodic surface modulation is observed in addition to a volume phase grating. An investigation has been carried out using white light interferometry into the dependence of the amplitude of the photo induced surface relief modulation on the spatial frequency, intensity of recording and sample thickness. The observed dependencies indicate that the diffusion of material during the holographic recording plays a major role in surface relief formation. The possibility for inscription of surface relief patterns opens the …

Micro Shot Blasting Of Machine Tools For Improving Surface Finish And Reducing Cutting Forces In Manufacturing, James Vahey, David Kennedy

Articles

Micro blasting of cutting tips and tools is a very effective and reliable method of advancing the life of tools under the action of turning, milling, drilling, punching and cutting. This paper outlines the ways in which micro blasted tools, both coated and un coated have benefited from shot blasting and resulted in greater productivity, lower cutting forces, improved surface finish of the work pieces and less machine downtime. The process of micro blasting is discussed in the paper. Its effectiveness depends on many parameters including the shot media ad size, the mechanics of impact and the application of the …