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Articles 3961 - 3990 of 4606

Full-Text Articles in Engineering

An Investigation On The Suitability Of Surface Engineered Austempered Ductile Iron As A Gear Material, M. Grech, David Kennedy, Zdravko Schauperl Jan 2005

An Investigation On The Suitability Of Surface Engineered Austempered Ductile Iron As A Gear Material, M. Grech, David Kennedy, Zdravko Schauperl

Conference Papers

This preliminary study demonstrates that surface engineered austempered ductile iron is a valid alternative gear material to carburised steel. The impact energy of ductile cast iron samples in various conditions, including as – cast, austempered at 240oC and austempered and shot peened using both 0.7mm and 1.4mm steel balls, was measured. As expected the as-cast material exhibited nominal impact energy. This has been attributed mainly to the pearlitic matrix structure.Austempering generally increases the impact energy. The extent of the improvement is however dependent on the austempering temperature and the resulting microstructure. It was shown that the structure following …

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Micro Shot Blasting Of Machine Tools For Improving Surface Finish And Reducing Cutting Forces In Manufacturing, James Vahey, David Kennedy Jan 2005

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 …

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A Gap Model For Understanding The Variation Of The Real Product From The Ideal, Kevin Delaney, Pat Phelan, Declan Delaney Jan 2005

A Gap Model For Understanding The Variation Of The Real Product From The Ideal, Kevin Delaney, Pat Phelan, Declan Delaney

Conference Papers

Clients have an idealised view of the appearance and functionality of the products they are sourcing. Their product requirements vary according to their specific circumstances and experiences. When designers try to meet or surpass client expectations, variation results and the product will deviate from the client’s idealised view. This often results in frustration, disappointment and rework for everyone concerned. Consequently designers must understand the sources of variation affecting their products and the techniques and tools that they can employ to reduce the negative effects of this variation. This paper examines the factors influencing clients as they formulate their expectations. It …

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Vibrational Coupling In Conjugated Π Systems With A View To Optimization Of Fluorescence Yield Through Phonon Confinement, Luke O'Neill, Patrick Lynch, Mary Mcnamara, Hugh Byrne Jan 2005

Vibrational Coupling In Conjugated Π Systems With A View To Optimization Of Fluorescence Yield Through Phonon Confinement, Luke O'Neill, Patrick Lynch, Mary Mcnamara, Hugh Byrne

Conference papers

A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Stokes shift also exhibited a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length. This correlation …

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Scm's Vital Role In B2b, Edward Sweeney Jan 2005

Scm's Vital Role In B2b, Edward Sweeney

Practitioner Journals

No abstract provided.

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Design Of A Wireless System For Patient-Hospital Communication And Result Validation In Point Of Care Testing, John Mcgrory, Owen Lynch, Eugene Coyle Jan 2005

Design Of A Wireless System For Patient-Hospital Communication And Result Validation In Point Of Care Testing, John Mcgrory, Owen Lynch, Eugene Coyle

Conference Papers

This paper discuses mobile phone (cell phone) and wireless applications for linking patients who manage their healthcare outside the hospital using Point of Care Testing (POCT) to hospital information systems (HIS). Certain medical conditions require patients to manage their healthcare by performing on themselves POC testing and act faithfully on the result. This raises quality control issue, as these POC samples and testing procedures are not independently overseen by professional hospital staff. In hospitals, samples taken by clinicians are validated by hi-tech computerised validation systems to ensure plausibility, before physicians rely on them. Patients in the home must often use …

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Attitudes Towards Electronic Purchasing In The Irish Construction Industry, Alan V. Hore, Roger West Jan 2005

Attitudes Towards Electronic Purchasing In The Irish Construction Industry, Alan V. Hore, Roger West

Conference papers

It is well known that the adoption of information technology in materials procurement in the construction industry has been sporadic and piecemeal. Very significant inefficiencies and problems still exist in both paper transactions and non-integrated electronic solutions. There is a general lack of awareness and take-up of information communication technologies (ICT) within the Irish construction material purchasing supply chain. In order to verify this contention a methodology was adopted which involved the design and distribution of an on-line questionnaire to over 100 Irish construction companies. The survey was designed to ascertain the current level of technology take-up in business-to-business (B2B) …

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An Examination Of The Effect Of Organisational Culture Of The Implementation Of Public-Private Partnership (Ppp) In Ireland, Louis Gunnigan, David Eaton Jan 2005

An Examination Of The Effect Of Organisational Culture Of The Implementation Of Public-Private Partnership (Ppp) In Ireland, Louis Gunnigan, David Eaton

Conference papers

This paper is concerned with identifying the organisational issues causing difficulty in the use of PPP and assessing the impact of PPP implementation on the organisational culture in the Irish public and private sectors. The authors address this issue by mapping the PPP process for one project type and comparing this process with that carried out in traditional procurement. Process differences through use of PPP are identified and organisational issues that have potential to impact on PPP success are assessed. Whilst the study undertaken is not extensive, it provides insight for initiators of PPP projects into the organisational issues that …

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Onset Detection, Music Transcription And Ornament Detection For The The Traditional Irish Fiddle, Aileen Kelleher, Derry Fitzgerald, Eugene Coyle, Robert Lawlor, Mikel Gainza Jan 2005

Onset Detection, Music Transcription And Ornament Detection For The The Traditional Irish Fiddle, Aileen Kelleher, Derry Fitzgerald, Eugene Coyle, Robert Lawlor, Mikel Gainza

Conference papers

By combining techniques used in previous onset detectors, a system that detects note onsets in traditional Irish fiddle tunes has been implemented. The notes detected also include the most common types of ornamentation played by the fiddle. Ornaments are notes of extremely short duration, at most a fifth the length of a regular note. A Short Time Fourier Transform based sub-band technique, which previously gave good results for the Irish tin whistle, was modified to include a threshold approximation more suitable for the fiddle. This system has been tested on a database of real recorded fiddle tunes and good results …

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Introducing Pvspitch: A Pitch Tracking Opcode For Csound, Alan O'Cinneide Jan 2005

Introducing Pvspitch: A Pitch Tracking Opcode For Csound, Alan O'Cinneide

Conference papers

An accurate pitch tracker has many useful applications, whether for creating interactive electroacoustic compositions, music transcription, ethnomusicological research and numerous others. Designed for the Csound sound synthesis and signal processing language, PVSPITCH is an opcode that can be utilised for such purposes. The opcode performs a mathemathical analysis upon Csound's phase vocoder data streams and from this examination, ascertains what it determines to be the signal's pitch. The algorithm handles well many types of signals, including those missing various harmonics, even a fundamental, and also signals with inharmonic partials. The only signal restriction are that it be single voiced, strongly …

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Generalised Prior Subspace Analysis For Polyphonic Pitch Transcription, Derry Fitzgerald, Matt Cranitch, Eugene Coyle Jan 2005

Generalised Prior Subspace Analysis For Polyphonic Pitch Transcription, Derry Fitzgerald, Matt Cranitch, Eugene Coyle

Conference papers

A reformulation of Prior Subspace Analysis (PSA) is presented, which restates the problem as that of fitting an undercomplete signal dictionary to a spectrogram. Further, a generalization of PSA is derived which allows the transcription of polyphonic pitched instruments. This involves the translation of a single frequency prior subspace of a note to approximate other notes, overcoming the problem of needing a separate basis function for each note played by an instrument. Examples are then demonstrated which show the utility of the generalised PSA algorithm for the purposes of polyphonic pitch transcription.

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Development Of A Computer-Based Violin Teaching Aid: Vitool, Jane Charles, Derry Fitzgerald, Eugene Coyle Jan 2005

Development Of A Computer-Based Violin Teaching Aid: Vitool, Jane Charles, Derry Fitzgerald, Eugene Coyle

Conference papers

This paper considers the development of a violin teaching aid, called ViTool, which is based on violin pedagogy, sound analysis, and comparison of beginner and good player recordings. It is a computer based teaching aid and will ultimately consist of at least four task dependent tools. Typical beginner faults have been identified and features, that best describe them for classification purposes, are considered. The ViTool is not intended as a replacement or electronic teacher, but as a teaching aid. Presently, it seems that no such violin learning aid or tool exists and an opportunity exists for the development of such …

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Single Channel Source Separation Using Short-Time Independent Component Analysis, Dan Barry, Derry Fitzgerald, Eugene Coyle Jan 2005

Single Channel Source Separation Using Short-Time Independent Component Analysis, Dan Barry, Derry Fitzgerald, Eugene Coyle

Conference papers

In this paper we develop a method for the sound source separation of single channel mixtures using Independent Component Analysis within a time-frequency representation of the audio signal. We apply standard Independent Component Analysis techniques to contiguous magnitude frames of the short-time Fourier transform of the mixture. Provided that the amplitude envelopes of each source are sufficiently different, it can be seen that it is possible to recover the independent short-time power spectra of each source. A simple scoring scheme based on auditory scene analysis cues is then used to overcome the source ordering problem ultimately allowing each of the …

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An Explicit Mapping Between The Frequency Domain And The Time Domain Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov Jan 2005

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 …

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Website Engagibility: A Step Beyond Usability., Ronan Fitzpatrick, Peter Smith, Brendan O'Shea Jan 2005

Website Engagibility: A Step Beyond Usability., Ronan Fitzpatrick, Peter Smith, Brendan O'Shea

Conference papers

There is a continuing need for quality eCommerce websites which satisfy their owner’s perspective of quality of design and visitor’s perspective of quality of use. More particularly there is a need for website owners to be able to specify what constitutes a website that will fully engage site visitors and consequently what needs to be designed into the website in order to insure return on investment. This paper argues that the term usability is inappropriate to quality websites and that website engagibility is a step beyond usability. The paper reports continuing research which seeks to identify the requirements of website …

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Experiences Teaching Website Engagibility To Computer Science Students., Pan Liqiang, Bryan Duggan, Ronan Fitzpatrick Jan 2005

Experiences Teaching Website Engagibility To Computer Science Students., Pan Liqiang, Bryan Duggan, Ronan Fitzpatrick

Conference papers

In the second year of our degree program, DT228 students study a subject called Web Development. In this paper we describe our studio classroom based teaching approach to this subject and explain how using this approach has enabled us to expand the scope of the course to include the important concept of website engagibility. We present a summary of current theories on website engagibility and explain how we incorporated these theories into the course. We further describe an experiment which we carried out in order to encourage students to reflect on website engagibility and incorporate it into their continuous assessments.

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Using The Crytek Game Engine In The Technological University Dublin, Hugh Mcatamney, Brendan O'Shea, Fredrick Mtenzi Jan 2005

Using The Crytek Game Engine In The Technological University Dublin, Hugh Mcatamney, Brendan O'Shea, Fredrick Mtenzi

Conference papers

It is envisaged that within the next 10 years. the Technological University Dublin (DIT), Ireland’s largest third level university, will move to a new campus in Grangegorman, located in the north inner city of Dublin This site is currently being used as a hospital. It has twelve listed buildings and is located in a densely populated urban community. This paper describes how the Crytek 3D Game engine is being used to create a game MOD (modification) of the current hospital site, how it will be used in the construction and public consultation process of the new campus and how students …

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Audio Time-Scale Modification, David Dorran Jan 2005

Audio Time-Scale Modification, David Dorran

Doctoral

Audio time-scale modification is an audio effect that alters the duration of an audio signal without affecting its perceived local pitch and timbral characteristics. There are two broad categories of time-scale modifications algorithms, time-domain and frequency-domain. The computationally efficient time-domain techniques produce high quality results for single pitched signals such as speech, but do not cope well with more complex signals such as polyphonic music. The less efficient frequency-domain techniques have proven to be more robust and produce high quality results for a variety of signals; however they introduce a reverberant artefact into the output. This dissertation focuses on incorporating …

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Onset And Ornament Detection And Music Transcription For Monophonic Traditional Irish Music, Aileen Kelleher Jan 2005

Onset And Ornament Detection And Music Transcription For Monophonic Traditional Irish Music, Aileen Kelleher

Masters

To date, much has been... This abstract will be longer in due course!

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Novel Implementation Of An Adaptive Shared Control Braking System For A Wheeled Walking Aid, Eileen Young Jan 2005

Novel Implementation Of An Adaptive Shared Control Braking System For A Wheeled Walking Aid, Eileen Young

Masters

The focus of this thesis is to design, build and control a prototype walking aid. The frame of the prototype is based on a combination of features from standard, widely available, wheeled walking aids. The user drives the walking aid. New brakes are added to facilitate accurate sensitive controlled stopping of the aid either by the user or automatically. The braking is achieved by the novel use of hydraulic disc brakes as used on mountain bicycles. Braking force is modulated via a linear actuator stepping motor controlled by a local drive. Actualisation of control of both stepping motor and supervisor …

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Performance And Robustness Metrics For The Compensation Of Processes With Time Delay, Niall O'Connor Jan 2005

Performance And Robustness Metrics For The Compensation Of Processes With Time Delay, Niall O'Connor

Masters

Proportional-integral (PI) or proportional-integral-derivative (PID) controllers are still by far the most common form of automatic feedback control employed in the process industries at present. It is estimated that more than 90% of control loops in the process control industry are of the PID type. Unfortunately, it is a common occurrence, in the majority of industries where this type of control is employed, for the performance of PI/PID controlled processes to be poor. There are a number of factors influencing this poor performance, namely controller tuning problems, controller equipment design restrictions, deficiencies in control strategy design, etc. The research was …

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An Experimental Analysis Of The Call Capacity Of Ieee 802.11b Wireless Local Area Networks For Voip Telephony, Brian Keegan Jan 2005

An Experimental Analysis Of The Call Capacity Of Ieee 802.11b Wireless Local Area Networks For Voip Telephony, Brian Keegan

Masters

The use of the Internet to make phone calls is growing in popularity as the Voice over Internet protocol (VoIP) allows users to make phone calls virtually free of charge. The increased uptake of broadband services by domestic users will further increase the use of VoIP telephony. Furthermore, the emergence of low cost wireless networks (namely IEEE 802.11a/b/g WLANs) is expected to bring wireless VoIP into the mainstream. As the number of wireless hotspots increases more users will want to use VoIP calls wherever possible by connecting to open access points (AP). A major concern with VoIP is Quality of …

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Modelling And Control Of A Suspension System For Vehicle Applications, Padraig Dowds, Aidan O'Dwyer Jan 2005

Modelling And Control Of A Suspension System For Vehicle Applications, Padraig Dowds, Aidan O'Dwyer

Conference papers

This paper discusses the modelling of passive and active suspension systems in a car, and the subsequent design of appropriate feedback controllers for the active suspension system. The models will be investigated using a quarter car model and a full car model approach.

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A Reference Guide To Smith Predictor Based Methods For The Compensation Of Dead-Time Processes, Aidan O'Dwyer Jan 2005

A Reference Guide To Smith Predictor Based Methods For The Compensation Of Dead-Time Processes, Aidan O'Dwyer

Conference papers

An extensive literature exists on the compensation of time delayed processes. These compensation methods may be broadly divided into parameter optimised controllers, in which the controller parameters are adapted to the controller structure (the most common such controller is the proportional integral derivative, or PID, controller), and structurally optimised controllers, in which the controller structure and parameters are adapted optimally to the structure and parameters of the process model. Important structurally optimised compensator strategies are the Smith predictor and its variations. The purpose of this paper is to extract the essence of the developments in design, tuning and implementation of …

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Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Yue Zhang, Aidan O'Dwyer Jan 2005

Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Yue Zhang, Aidan O'Dwyer

Conference papers

All process investigations should start by a determination of the process model. The modeling strategy used will influence the value of the model parameters, which will in turn affect the controller values determined from tuning rules. This paper will describe an analytical method to identify a model of the dynamic characteristics of a process with a delay by using a tangent and point method, as originally suggested by Murrill, 1967. The methodology has been applied to eight benchmark transfer functions suitable for testing PID controllers, as suggested by Åström and Hägglund, 2000. The main advantages of the modeling approach are …

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Comparative Study Of Two Techniques For Determining Critical Frequency Response Characteristics, Niall O'Connor, Aidan O'Dwyer Jan 2005

Comparative Study Of Two Techniques For Determining Critical Frequency Response Characteristics, Niall O'Connor, Aidan O'Dwyer

Conference papers

The paper presents a review of a comparative study of two separate techniques for obtaining important frequency and time domain characteristics of a system consisting of a process in series with a PI/PID controller in closed loop. The first technique involves the use of a Pseudo Random Binary Sequence (PRBS) to obtain the closed loop frequency response of the system. This closed loop frequency information may then be manipulated to obtain both open loop frequency response information and process model parameters. A further mathematical simulation using Matlab may then be performed independent of the actual process in order to obtain …

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Pid Control: The Early Years, Aidan O'Dwyer Jan 2005

Pid Control: The Early Years, Aidan O'Dwyer

Conference papers

This contribution outlines controller developments 1788 – c.1900; 1900-1950: The role of instrument companies; early theoretical description of the PID controller; early tuning of the PID controller; some further developments since 1950; some conclusions.

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Dual-Band Monopole Antenna With Stagger-Tuned Arms For Broadbanding, Max Ammann, R. Farrell Jan 2005

Dual-Band Monopole Antenna With Stagger-Tuned Arms For Broadbanding, Max Ammann, R. Farrell

Conference papers

The paper describes a dual-band miniaturized printed monopole for integration in modern wireless systems. The printed monopole is augmented with two arms, resonant at slightly different frequencies, providing a broadened response for the upper band. The achieved bandwidth for the high band is 36%. These antennas are proposed for the emerging dual-mode multi-band WLAN transceivers, which operate over a wide range of bands as dictated by national authorities. Measured and simulated data, including return loss, antenna gain and radiation patterns, are presented. The numerical method employed was the finite integration technique.

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Learning Games Programming With Dalek World., Bryan Duggan, Hugh Mcatamney, Fredrick Mtenzi Jan 2005

Learning Games Programming With Dalek World., Bryan Duggan, Hugh Mcatamney, Fredrick Mtenzi

Conference papers

From September 2005 the School of Computing in the DIT will offer an elective in computer games programming to final year computer science students. This paper demonstrates how students will learn games programming by developing a 3D FPS (First Person Shooter) called Dalek World. Dalek World is developed using Microsoft Visual Studio in C++ and was originally developed by the authors to learn games programming techniques themselves. In developing Dalek World, students will learn Euclidian geometry, 3D graphics programming, object orientated game design, level loading, physics, collision detection, the A* algorithm, perception and enemy AI using finite state machines.

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Bs News Jan 2005

Bs News

Building Services Engineering

No abstract provided.

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