Engineering Commons^™

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 …

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 …

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.

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 …

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 …

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 …

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 …

Rationalising The Construction Materials Purchasing Process, Louis Gunnigan, Alan V. Hore, Trevor Orr

Conference papers

This paper is concerned with the process used in locating and removing inefficiency in the construction materials purchasing process. In the first part, a case study is presented showing the build-up of costs involved in purchasing materials. Potential for substantial savings is revealed. The second part of the paper gives a status report on a rationalisation pilot project currently being undertaken by the Construction Information Technology Alliance (CITA). This project aims to show how greater effectiveness and efficiency can be applied to the administration of the construction materials purchasing process by the application of information technology already used widely in …

Rhythmic Parsing Of Sonified Dna And Rna Sequences, Charlie Cullen, Eugene Coyle

Conference papers

Sonification allows existing mathematical data to be used as the model for audio output, notably that the audio produced is related to or representative of that data in some way. Existing work in the field has been largely focused on the aesthetic tailoring of the output audio for compositional benefit rather than as a framework for audio representation and analysis. It is the goal of this research to apply existing techniques for pitch substitution to an analytical method that seeks to define and represent patterns within existing data sets (primarily DNA and RNA sequences). It is often the case that …

Independent Subspace Analysis Using Locally Linear Embedding, Derry Fitzgerald, Eugene Coyle

Conference papers

While Independent Subspace Analysis provides a means of blindly separating sound souces from a single channel signal, it does have a number of problems. In particular the amount of information required for separation of sources varies with the signal. This is a result of the variance-based nature of Principal Component Analysis, which is used for dimensional reduction in the Independent Subspace Analysis algorithm. In an attempt to overcome this problem the use of a non-variance based dimensional reduction method, Locally Linear Embedding, is proposed. Locally Linear Embedding is a geometry based dimensional reduction technique. The use of this approach is …

High Auality Time-Scale Modification Of Speech Using A Peak Alignment Overlap-Add Alogroithm (Paola), David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

The duration of a speech passage can be altered using audio time-scale modification techniques. Time-scale modification can be achieved in the time domain by segmenting the input signal into overlapping frames and recombining the frames with an overlap differing from the analysis overlap. We present a time-scale modification algorithm that uses a simple peak alignment technique to synchronise overlapping synthesis frames. The peak alignment overlap-add (Paola) algorithm also takes advantage of waveform properties to ensure a high quality output for the minimum number of iterations. The new algorithm produces a time-scaled output of approximately equal quality to that of an …

Drum Transcription Using Automatic Grouping Of Events And Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Coyle

Conference papers

While Prior Subspace Analysis (PSA) has proved an effective tool for transcribung mixtures of snare, kick drum and hi-hat, attempts to extend it to increased numbers of drum types have met with mixed results. To overcome this an automatic grouping method has been developed to group drum events on their similarity in frequency content. Combined with PSA this creates a system able to handle robustly greater numbers of drum types. The effectiveness of this method is demonstrated in a drum transcription algorithm.

An Outline And Further Development Of Smith Predictor Based Methods For The Compensation Of Processes With Time Delay, Pauline Sourdille, Aidan O'Dwyer

Conference papers

An extensive literature review is presented and a new modified Smith predictor is subsequently presented.

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

Conference papers

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 ISE performance index value for a 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 use of tuning rules. The second part of this paper …

System Identification Using Higher Order Spectra, Aidan O'Dwyer

Conference papers

This communication will explore the use of particular types of frequency domain concepts, labelled higher order spectra, to help determine the frequency response of a process. This will allow the identification of the parameters of a single input, single output (SISO) model for a process (which includes a time delay), in both open loop and closed loop environments.

On Stability Of Affine Blending Systems, Ruiyao Gao, Aidan O'Dwyer, Seamus Mcloone, Eugene Coyle

Conference papers

This paper presents a novel approach to stability analysis of affine blending systems. The analysis is based on Quadratic Lyapunov functions. The approach considers the nonlinear offset term in affine blending systems as non-vanishing perturbations added to the corresponding nominal linear blending systems. The affine blending systems will be bounded if the corresponding linear blending system is exponentially stable. The bound is determined by an ultimate limit, which is proportional to the maximum of the offset terms of each affine system.

New Modified Smith Predictor Designs, Pauline Sourdille, Aidan O'Dwyer

Conference papers

By combining several existing modified Smith predictor structures, presented in a literature review, a generalised form of the Smith predictor is proposed. From this structure, excellent servo and regulator responses can be obtained by specifying three controller dynamic elements. Two new modified Smith predictor structures are presented with their associated tuning rules. The results of the simulations indicate that the two new designs give better overall responses than the original Smith predictor.

Pid Compensation Of Time Delayed Processes 1998-2002: A Survey, Aidan O'Dwyer

Conference papers

A time delay may be defined as the time interval between the start of an event at one point in a system and its resulting action at another point in the system. Delays are also known as transport lags or dead times; they arise in physical, chemical, biological and economic systems, as well as in the process of measurement and computation. Methods for the compensation of time delayed processes may be broadly divided into proportional integral derivative (PID) based controllers, in which the controller parameters are adapted to the controller structure, and structurally optimised controllers, in which the controller structure …

Crafting A Research Paper, Ronan Fitzpatrick, Kevin O'Donnell

Conference papers

Writing research papers presents numerous different challenges, which vary from how to layout the various pages and format the text to what to include in the different sections that make up the paper. In order to clarify these issues this paper sets out guidelines and best practice approaches and demonstrates their use in the style of this paper.

Quality Challenges In E-Commerce Websites, Ronan Fitzpatrick

Conference papers

No abstract provided.

Speech-Adaptive Time-Scale Modification For Computer Assisted Language Learning, Olivia Donnellan, Elmar Jung, Eugene Coyle

Conference papers

In traditional foreign language learning programmes students are offered a tutor model characterised by slow, deliberate speech. This is insufficient to prepare them to cope with native, colloquial speech. By applying a timescale modification (TSM) algorithm to natural-speed, native speech, students have access to a more desirable, natural speech corpus which permits them to practise essential listening skills in a more focussed manner. This paper presents a method which allows slowing down speech without compromising the quality, pitch or naturalness of the slowed speech by applying different scaling factors to different types of speech segments. The new method is compared …

Modified Planar Inverted-L Antenna, Jonathan Evans, Max Ammann

Conference papers

A hybrid inverted-L antenna (HIL) has been shown to reduce the physical height of a square planar monopole antenna, while retaining a relatively wide impedance bandwidth and good radiation pattern characteristics. The introduction of horizontal slots in the vertical edges of the antenna cause the surface current to meander, resulting in a decrease in the lower edge frequency of the impedance bandwidth. The impact of different sizes and arrangements of slots on impedance and radiation pattern bandwidth, gain and surface current distribution is simulated using transmission line modelling (TLM). Simulated results for impedance bandwidth are verified with measurements. With other …

Improved Pattern Stability For Monopole Antennas With Ultrawideband Impedance Characteristics, Max Ammann

Conference papers

The requirement of future software defined and reconfigurable radio networks to operate in multiple, wide-ranging, frequency bands places heavy demands on antenna designs. Rather than using antennas tuned at the time of manufacture to operate in certain predefined frequency bands under predefined radio systems, which limits the possibilities of implementing new radio systems on a reconfigurable terminal, a wideband antenna is proposed. The use of a single antenna which can operate over many octaves is very desirable for future wireless communications systems. We discuss the characteristics of the planar monopole, an antenna with wideband properties. The addition of a second …