Engineering Commons^™

Turning An Articulated Truck On A Spreadsheet, Jim Mcgovern

Articles

This paper describes how a standard office spreadsheet application was used to set up an engineering model for the simulation and analysis of the turning of articulated trucks

Finite Element Modelling Of Moisture Movement In Concrete Floors, Niall Holmes, Roger West

Conference papers

Predictive methods for determining the point at which it is safe to apply floor coverings to concrete floors can save time and money for the client, contractor and the floor installer. The current standard states that impervious floor coverings should not be applied until the surface of the floor reaches a relative humidity (RH) of 75%, established using a surface hygrometer test. Tests at Trinity College Dublin on drying concrete slabs in natural and forced drying environments show that there is a large variation in the residue of moisture deep in the concrete when the floor covering is applied, particularly …

An Examination Of Eu Directive 98/76/Ec In Regards To The Irish Road Haulage Industry, Eoin Plant, Declan Allen, Edward Sweeney

Conference papers

The Irish economy experienced a tremendous increase in economic growth during the 1990s and early 21st Century (Celtic Tiger). This economic boom was export driven and the Irish Road Haulage Industry transported the majority of products produced at some stage, if not a number of stages in the logistics tunnel. In recent times there has been somewhat of a growing unease in the road haulage industry in relation to increasing costs, squeezing already tight profit margins. A report commissioned by the Department of Public Enterprise illustrated that 48% of hauliers identified themselves as needing training in the area of cost …

Identification And Pid Control Of Time-Delayed Processes, Tony Kealy

Masters

This research was conducted primarily to investigate a selection of known methods for the identification of a mathematical model for processes with an inherent time delay, and subsequently, use the parameters of the identified model to regulate the processes via the PI/PID control strategy. The research examines the level of difficulty in performing or sanctioning different system identification methods in order to re-tune the controller. The process model identification methods are carried out on both simulated and real processes in the first part of the research. The selected parametric identification methods are chosen because they encompass open- and closed- loop …

Moisture Re-Distribution In Concrete Under Impermeable Coverings, Niall Holmes

Conference papers

It is normally considered safe to apply an impermeable floor covering to concrete surfaces when the surface relative humidity reaches 75% as determined by a surface hygrometer. However, over time, defects can appear on the covering such as blistering of vinyl and rising of tiles from the surface. One cause is the on-going diffusion of the residual moisture deep within the slab to the surface. The covering traps this residual moisture, thus preventing evaporation to the ambient air and gradually generates a vapour pressure underneath the covering, which can result in damage.

Here, experimental results on the long-term influence of …

The Estimation And Control Of A Laboratory Heating And Ventilation System, Robin P. Mooney

Masters in Advanced Engineering

This dissertation is concerned with the estimation and control of a laboratory heating and ventilation system (Instrutek VVS-400). The system is a 2x2 multi-input multi-output process (MIMO). It has been shown that simple techniques such as the ultimate cycle method do not provide adequate control of the process. The system was interfaced with a PC using Matlab/Simulink via a data acquisition package (Humusoft). Continuous time process identification techniques were applied to the flow and temperature processes. The alternative tangent and point method was used to model the processes, and their interaction, using a first order lag plus delay model. Models …

Ict Adoption And Impact On The Italian Logistics Service Providers’ Performance, Pietro Evangelista, Riccardo Mogre, Alessandro Perego, Antonino Raspagliesi, Edward Sweeney

Conference papers

No abstract provided.

Engineering Is Fun - Let's Celebrate, Jim Mcgovern

Articles

In this news article the author outlines why the Faculty of Engineering at DIT and all its professional engineering graduates have cause to celebrate 50 years of engineering at DIT from September 2003.

Comparison Of Process Identification Techniqies In The Time- And Frequency-Domains, Tony Kealy, Aidan O'Dwyer

Conference papers

This paper describes ten methods to identify a mathematical model for a real process with a time delay. The process is the Process Trainer, PT326 from Feedback Instruments Limited. Six of the methods use step response data and one of the methods uses impulse response data for identification. Two of the methods use frequency response data and the final method uses information from relay-based experiments. The best results are obtained using a combined analytical and gradient method [6] in the frequency-domain and, in the time-domain, using the two-point algorithm [1] and a method proposed by Suganda et al. [5].

Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer

Conference papers

Abstract – In control system theory, a performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system parameters. In this paper, the authors demonstrate two methods to determine analytically the Integral of the Square of the Error (ISE) performance index value for a first-order-plus-dead-time (FOPDT) process model under PI control. The ability of proportional/integral (PI) and proportional/integral/derivative (PID) controllers to compensate most practical industrial processes has led to their wide acceptance in industrial applications. The most direct way to set up PI/PID controller parameters is the …

An Investigation Into Non-Verbal Sound-Based Modes Of Human-To-Computer Communication With Rehabilitation Applications, Ted Burke

Conference Papers

During the course of our work in the National Rehabilitation Hospital in Ireland we have encountered patients who, while unable to speak, are capable of making reproducible utterances. We present techniques used to harness such utterances, in addition to whistling, as a means of communication and control. A simple technique for identifying the phonemes /o/ and /s/ (in single-symbol ARPAbet notation) is presented with applications. The use of pitch variation as a means of controlling a continuously variable parameter is described with two applications - a microcontroller based light dimmer switch and a computer program which facilitates mouse pointer control. …

Application Of Time-Scale And Frequency-Scale Modification Alogrithms To Voice-Gender Conversion, Elmar Jung

Masters

Voice conversion is an active new branch of speech processing and deals with the transformation of natural speech, focusing on changing the characteristics of the speaker’s voice. As a result of voice conversion, the speaker’s identity can be changed to make the converted speech sound as if it were uttered by a different speaker, or certain characteristics of the voice can be modified while maintaining the speaker’s identity. Voice-gender conversion (VGC) is a subset of voice conversion and focuses on the transformation of gender-specific voice characteristics. As a result of a voice-gender conversation, male speech is converted into female-sounding speech …

The Influence Of Surface Treatments And Surface Finish On The Fatigue Properties Of Elastomers, Amir Tabakovic

Masters

Recent research has shown that fatigue life in non strain-crystallising rubber increases if the material is subjected to pre-loading. The central research question posed in this project is ‘whether preloading and surface treatments improve the surface finish of rubber components, reduce stress concentration and can this reduction partially account for greater fatigue resistance’. The specific objectives of the research are:- i) To assess surface finish measurements and to investigate the changes in stress concentration in preloaded rubber samples using White Light Interferometry. ii) To consider other non-contact methods of observing changes in stress concentration in preloaded samples through use of: …

Rainwater Harvesting And Grey Water Recycling Systems, Liam Mccarton, Sean O'Hogain

Articles

The benefits of water efficiency measures, rainwater harvesting and greywater reuse are principally water savings and reduced volume of consumption. Cost savings can accrue to the water supplier and water user. These benefits can be felt at a local level. Only with widespread use of such technology will reduced pressure on water resources and the supply infrastructure be realised. These technologies should be considered in the context of an overall water conservation strategy and each situation evaluated separately. A water audit should be undertaken to establish existing water usage and possible demands that can be met by using these technologies. …

Water Conservation Technologies, Liam Mccarton

Articles

Given the increasing incidence of serious flooding in Europe in recent years it might seem odd to be addressing the problem of water conservation. However, recent economic prosperity has led to an increased per capita use of water for domestic and industrial use. The traditional approach to meeting increased demand is to augment supply. However, mobilising new resources involves ever higher costs. Allied to this is the concept of sustainability, which can be defined as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’. An important consideration of …

Circular Annular Planar Monopoles With Em Coupling, Z. N. Chen, Max Ammann, M.Y. W. Chia, T.S. P. See

Articles

A circular annular planar monopole with electromagnetic coupling shows broadband properties. The planar radiator is electromagnetically coupled with a probe-fed strip, and separated from it by a thin dielectric sheet. The parametric effects on the bandwidth are examined experimentally. The measurements demonstrate that the proposed monopoles have the merit of broad impedance bandwidths in the order of 100% for VSWR=2:1 and of 4:1 for VSWR=3:1 and acceptable radiation patterns across the bandwidths.

Prior Subspace Analysis For Drum Transcription, Derry Fitzgerald, Robert Lawlor, Eugene Coyle

Conference papers

This paper introduces the technique of Prior Subspace Analysis (PSA) as an alternative to Independent Subspace Analysis (ISA) in cases where prior knowledge about the sources to be separated is available. The use of prior knowledge overcomes some of the problems associated with ISA, in particular the problem of estimating the amount of information required for separation. This results in improved robustness for drum transcription purposes. Prior knowledge is incorporated by use of a set of prior frequency subspaces that characterise features of the sources to be extracted. The effectiveness and robustness of PSA is demonstrated by its use in …

Phase Balancing And Harmonic Mitigation For Large Electrical Loads, Hugh O'Kelly

Masters

This thesis describes the development and implementation of new solutions to the power quality problems associated with large unbalanced and non-linear loads. The thesis was undertaken in the context of the fine glass industry and the development work was carried out at three production plants belonging to a world leading fine glass producer. In the process of fine glass production, furnaces are used to melt the silica mix into a liquid of treacle consistency. These furnaces are generally enclosed, except for several small orifices about 50 mm in diameter, which are located around their perimeter. Through these openings, glass blowers …

Time Scale Modification Of Music Using A Subband Approach Based On The Bark Scale, David Dorran, Robert Lawlor

Conference papers

Time-domain time-scaling algorithms are efficient in comparison to their frequency-domain counterparts, but they rely upon the existence of a quasi-periodic signal to produce a high quality output. This requirement makes them unsuitable for use on multi-pitched signals such as polyphonic music. However, time-domain techniques applied on a subband basis can resolve the multi-pitch problem. The authors propose an improved subband implementation based upon the bark scale for the time scale modification of music. The new subband approach is supported by psychoacoustic and music theory and subjectively through informal listening tests.

An Efficient Audio Time-Scale Modification Algorithm For Use In A Subband Implementation, David Dorran, Robert Lawlor

Conference papers

The Paola algorithm, is an efficient algorithm for the time scale modification of speech. It uses a simple peak alignment technique to synchronise synthesis frames and takes waveform properties and the desired time-scale factor into account to determine optimum alogrithm parameters. However, PAOLA has difficulties with certain waveform types and can result in poor synchronisation for subband implementations. SOLA is a less efficient algorithm but resolves the issues associated with PAOLA's implementation. The authors present an algorithm that is a combination of the two approaches that proves to be an efficient and effective algorithm for a subband implementation.

Time-Scale Modification Of Speech Using A Synchronised And Adaptive Overlap-Add (Saola) Algorithm, David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

The synchonised overlap-add (SOLA) algorithm is a commercially popular and considerably researched audio time-scale modification technique. It operates in the time domain and uses a correlation technique to ensure that synthesis frames overlap in a synchronous manner. We present a modification to SOLA that allows the analysis step size adapt to the desired time-scale factor. The synchronised and adaptive overlap-add (SAOLA) alogorithm improves upon the output quality of SOLA for high time-scale factors and reduces the computational requirements for low time-scale factors. However, the computational requirements for high time-scale factors are increased.

Drum Transcription In The Presence Of Pitched Instruments Using Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Coyle

Conference papers

This paper demonstrates the use of Prior Subspace Analysis (PSA) as a method for transcribing drums in the presence of pitched instruments. PSA uses prior subspaces that represent the sources to be transcribed to overcome some of the problems associated with other subspace methods such as Independent Subspace Analysis (ISA) or sub-band ISA. The use of prior knowledge results in improved robustness for transcription purposes and enables the method to work more readily in the presence of pitched instruments than other subspace methods. The system presented in this paper attempts to extend the use of PSA to transcribe drum sounds …

Evaluation Of Scheduling Strategies On The Performance Of A Flexible Manufacturing Cell:A Simulation Study, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

The current trend in semiconductor manufacturing is characterized by expanding product variety, decreasing lead times from order to delivery, exacting standards of quality, and competitive prices. One possible means of achieving this is in the form of increased flexibility. Providing flexibility is typically an expensive proposition so, industrial engineers aim to provide more economic approaches to enable flexible manufacturing cells and related equipment to operate appropriately in an efficient manner. It is essential to characterize these tools in detail before the production plans are finalized. Using state-of-the-art computer simulation, a generic model of photolithography tools has been developed. The model …

Experimental Energy Performance Of Open Cooling Towers Used Under Low And Variable Approach Conditions For Indirect Evaporative Cooling Of Buildings, Ben Costelloe, Donal Finn

Articles

The success of chilled ceilings and displacement ventilation systems as a means of sensible cooling in buildings has prompted a review of evaporative cooling technology as an effective means of generating the required cooling water. When such cooling water is generated at low approach conditions (2–5 K), at the higher temperatures required in these systems (14–18°C), very high levels of availability result. In many north western European locations the levels of availability are such that the prospect of supplanting rather than simply supplementing the refrigeration system, for sensible cooling purposes, arises. The viability of the technique, however, largely depends on …

Managing Content-Initiated Application Delivery With A Client-Side Agent, Niall Roche, Gary Clynch

Conference Papers

Mobile devices have evolved with improvements in processing power and support for various application environments such as MExE [1]. Currently a large number of devices and platforms exist, each with various attributes. Such diversity results in problems providing appropriate applications to these devices. This paper outlines need for an integrated approach to application delivery for mobile devices. The solution allows suitable applications to be delivered to devices. Application management is removed from non-technical mobile device users through the presence of a client-side agent to manage the complexity of application provisioning, device resource management and application management.

Optical Switches Using Electro-Optical Effects In Liquid Crystals, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell

Articles

A simple displacement sensor based on a bent singlemode-multimode-singlemode (SMS) fiber structure is proposed and experimentally investigated. The sensor offers a wider displacement range, not limited by the risk of fiber breakage, as well as a three-fold increase in displacement sensitivity by comparison with a straight SMS structure sensor. This sensor can be interrogated by either an optical spectral analyzer (OSA) or a ratiometric interrogation system: (1) if interrogated by an OSA assuming a resolution of 1 pm, it has a sensitivity of 28.2 nm for a displacement measurement range from 0 to 280 μm; (2) if interrogated by a …

Design Criteria And Optical Characteristics Of One-Dimensional Photonic Crystals Based On Periodically Grooved Silicon, Vladimir Tolmachev, Tatiana Perova, Kevin Berwick

Articles

Photonic bandgap (PBG) regions have been calculated for periodically grooved Si structures, acting as a one-dimensional photonic crystal. The wavelength range of the PBG as a function of the ratio (D_Si/A) is presented, where D_Si is the width of the Si walls and A is the grooved silicon lattice constant. The influence of the parameter D_Si, the refractive index of the space between the Si walls and the number of structure periods, m, on the forming of PBG regions is discussed. A good correlation between the calculated and the experimentally observed …

Study Of Structure And Quality Of Different Silicon Oxides Using Ftir And Raman Microscopy, C. Moore, T. S. Perova, B. Kennedy, Kevin Berwick, I. I. Shaganov, R. A. Moore

Articles

In this work, SiO₂ and fluorine and phosphorous doped SiO₂ thin films are investigated using FTIR and Raman techniques. FTIR spectroscopy was performed at normal and oblique incidence of the probe beam in transmission and reflection modes. The effect of polarisation and angle of incidence of the probe beam is examined for the case of reflection mode. Infrared spectra taken from doped oxides show that the structure changes with the passage of time. Alternate methods to calculate the thickness of the doped film are therefore discussed. Infrared spectra of electron beam evaporated oxides give valuable information on their …

Site-Specific Probabilistic Load Modelling For Bridge Reliability Analysis, Colin C. Caprani, A. Belay, A. J. O'Connor

Conference papers

Reliability assessment of a short span beam-slab reinforced concrete bridge in Vienna is proposed using site-specific traffic data recorded using the Slovenian Weigh in Motion (SiWIM) system. An initial evaluation of the bridge using a determinintic approach shows that the critical limit state is bending. This paper describes the statistical analysis of the SiWIM data and the traffic flow simulations performed to predict the characteristic extreme load effects to which the bridge may be subjected during its remaining lifetime. These values are compared to the magnitude obtained from a deterministic approach. The influence lines used in the simulations are the …

A Reflection On The Development, Activities And Deliverables Of The Construction It Alliance (Cita) In Ireland, Ken Thomas, Alan V. Hore

Conference papers

This paper reflects on the development, activities and deliverables of the Construction IT Alliance in the Republic of Ireland. This alliance was formed in 2001 with the vision of harnessing the potential of information and communication technologies in the Irish construction sector. CITA is a prime example of academia-industry-government collaboration in Ireland. A key driver in the development of CITA is the need to increase the extent of IT knowledge within the Irish construction sector. Membership of CITA includes leading architectural, engineering, surveying, management, construction, supplier, IT and academic organisations. The leading academic institutions in CITA are the Technological University …