Digital Commons Network^™

Air Intake Cooling Motor Vehicle Performance Enhancement, James Brunton, David Kennedy, John D. Kelleher

Articles

This research examined the practical effects of cooling the intake air, on the combustion characteristics of a modern motor vehicle operating under simulated road conditions as well as its subsequent impact on the environment. The cooling effect was achieved by taking a typical air conditioning rig as fitted to a modern motor vehicle and incorporating it into the induction system of the car. The test vehicle used was a 1993 Renault Safrane 2.0Vi standard passenger car that was modified as part of the research to facilitate the extraction of the required test information. A series of tests were conducted using …

Elastomeric Hoof Boots, John Hanley

Masters

The design, manufacture and testing of a prototype elastomeric equine boot is described in this thesis. Thoroughbred horses may suffer from a number of serious hoof disorders. These include stone bruising, navicular syndrome and hoof wall separation. Excessive concussion in the equine hoof is a major contributory factor in most of the problems horses experience in their lower limbs. Bandaging of a horses foot after injury is time consuming as well as being labour intensive. The proposed boot serves a number of purposes; by replacing bandages during poulticing it plays a part in faster healing of foot ailments. It can …

Bs News

Building Services Engineering

No abstract provided.

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 …

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 …

Environmental Planning, Steven Konkel

Books/Book chapters

No abstract provided.

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.

Optimization And Comparison Of Broadband Monopoles, Z. N. Chen, M.Y. W. Chia, Max Ammann

Articles

The impedance and radiation properties of four broadband monopoles are compared and the parameters of a new roll monopole are optimised experimentally and numerically. The performances of the roll monopole with various numbers of roll turns are discussed and optimised numerically. The measurements and simulations show that, compared with conventional broadband monopoles, the roll monopole

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 …

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

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.

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.

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 …

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.

Analysis Of Cooling And Heating Of Water With Flat-Plate Solar Radiators, Igor Balen, Vladimir Soldo, David Kennedy

Conference Papers

Extensive analysis of flat-plate radiative panels operation using average hourly weather data for a maritime climate region was performed. The panels are integrated in the space ventilation system with air-cooling by means of a cold-water coil. Their primary function is to prepare sufficient quantity of cold water, integrating radiative and convective cooling, that is collected in the cold-water tank during the nighttime operation. That cold water is used for cooling of the air during daytime. By small modification during daytime, solar panels could be turned into collectors and used to produce the hot water that is collected in a separate …

Solution Of The Navier-Stokes Equations For Transonic Propeller Flows, Fergal Boyle

Conference Papers

The three-dimensional, compressible, viscous flow field around a general propeller geometry with the inflow at zero angles of incidence and yaw is computed using a Reynolds-Averaged Navier-Stokes equations solver. Results from validation test cases in which the laminar and turbulent incompressible flow over a flat plate are calculated demonstrate the flow solver is capable of accurately capturing boundary-layer behaviour. Euler solutions from flow field calculations around two very different propeller geometries show a high level of accuracy and efficiency. Preliminary results from a viscous flow field calculation around a two-bladed propeller are very encouraging.

The Dogs Bollox, Special War Edition, Vol. 1, Issue 2, 2003, Dit: Students' Union

DIT Student Union

No abstract provided.

Searching For Greater Variety In Strategic Thinking, Brendan O'Rourke, Martyn Pitt

Conference papers

This paper proposes a use of the discursive approach to explicate variety in ways of strategic thinking. Such an explication of variety is both useful managerially in increasing awareness of greater discursive resources and also theoretically in critiquing views of strategic thinking as homogenous and organizationally contained. Ways of strategic thinking have been investigated using a variety of approaches including expertise perspectives (Voss, Greene et al. 1983), cognitive mapping (Eden, Jones et al. (1979); Huff (1990) ) and upper echelon theory (Hambrick 1998). More recently the linguistic turn in organizational sciences (Alvesson and Kärreman 2000), and the study of strategy …

Retailing At The Periphery: An Analysis Of Dublin’S Tertiary City-Centre Shopping Streets (1972-2002), Edmund O'Callaghan, Don O'Riordan

Articles

This research examined changes in Dublin’s tertiary city centre shopping streets over a thirty year period to 2002. An observational study of the occupancy of the city’s tertiary streetscape was undertaken in the summer of 2002 and compared with historical data. Results indicate significant change over the period examined: an increased vacancy rate, a very low survival rate, a considerable incidence of non retail specific activities, a decline in traditional retail offerings and the emergence of new categories of retailer. The paper concludes by suggesting a proactive approach is required by present day retailers in the tertiary streets to ensure …

The Implications Of The Curriculum Process On The Design Of A Modern Engineering Programme In The Dublin Institute Of Technology, Kevin Kelly

Level 3

In the Dublin Institute of Technology (DIT) the curriculum usually starts with a programme document. The programme document will be a snapshot of faculty thinking at a point in time, usually at the validation stage of the programme. The programme document lays down clearly the aims, objectives, facilities, staff, syllabi, learning/teaching methods, assessment procedures, programme-management arrangements and all of the other characteristics of the programme. It provides a basis for critical scrutiny by all involved. Compilation of the document is an iterative process, and the final document is scrutinised by an expert panel as part of the validation process.

Healthy Cities, Julie Gannon

Articles

No abstract provided.

Integrating The Use Of Teaching Portfolios With Experiential Learning In A Postgraduate Certificate For Academic Staff In Third Level Learning And Teaching, Roisin Donnelly

Journal Articles

No abstract provided.

Sharing Systems, Sharing Language: Designing And Working In A Virtual Department, Claire Mcavinia, Jane Hughes

Journal Articles

Less widely taught languages present special problems. Often students may be ab initio learners who must progress very rapidly from beginner to highly competent. Appropriate learning materials are scarce. Small student numbers restrict the range of learner tasks. To address these problems, and drawing on research methods from both CALL and Computer Science domains, we investigated the use of a virtual learning environment (WebCT) as a tool for collaborative language teaching and learning. A web-based virtual department was created, bringing students and tutors from different institutions together to practise the target language (students) and share the development of quality resources …

2003 : Part-Time Programmes, Dublin Institute Of Technology

DIT Publications

Book containing information and full list of part - time courses for 2003 entry.

2003/2004 academic calendar.

Faculty structure and key contacts at DIT.

Enhanced Magnetoresistance In Nanocrystalline Magnetite, M Venkatesan, S. Nawka, Suresh Pillai, Jm D. Coey

Articles

The magnetic and magnetotransport properties of nanoparticulate magnetite with different grain
sizes are investigated using x-ray diffraction, microscopy, magnetometry, and magnetoresistance
measurements. The magnetization varies significantly with grain size and is sensitive to preparation conditions. The reduction in saturation magnetization in coprecipitated particles is probably due to the surface spin disorder. Magnetoresistance of pressed powder compacts is significantly enhanced
in material composed of small grain size magnetite particles prepared by coprecipitation. Useful
magnetoresistance persists well above room temperature in sintered ceramic material.

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.

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 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.

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 …