Engineering Commons^™

Bs News

Building Services Engineering

No abstract provided.

Fighting Back In Hard Times: The 1990 Strike In Waterford Crystal, Eddie Conlon

Conference papers

No abstract provided.

Compensation Of Processes With Time Delays, Thomas Heeg, Aidan O'Dwyer

Conference papers

Methods which allow comparisons in the use of PI and PID controller strategies for the control of first order lag plus time delay processes (FOLPD) are worthy of investigation because of the relative lack of work done in this area. In this paper, strategies for comparing performance and robustness for a PI or PID controlled FOLPD process are analysed and designed. The use of different PID controller structures for processes with time delay is also worth considering in detail. Various PID controller structures are compared by means of servo and regulator time responses, Bode plots and Nyquist plots.

The Identification And Control Of Processes With Time Delay, Susan Carr, Aidan O'Dwyer

Conference papers

The identification of the frequency response and process model parameters of systems with time delay using frequency domain techniques is evaluated in this paper. The performance of both Fourier Transform and Power Spectral Density techniques is considered. The benefits of employing modern model based design and delay compensation techniques, based on the identified process data, are assessed.

Evaluation Of Implicit Numerical Methods For Building Energy Simulation, Michael Crowley, Saleem Hashmi

Articles

The stability of numerical methods used for finite-difference thermal modelling of buildings is discussed. A known instability in a commonly used process is described and alternative numerical methods with suitable stability properties are identified. With a view to selecting the optimum numerical method, the building energy simulation problem is characterized mathematically and appropriate implicit solvers are compared on the basis of accuracy and computational effort using a building related test problem prepared for this purpose. A recently developed numerical method with the necessary strong stability is found to possess higher computational efficiency than methods frequently used in this application and …

Strategies For Evaluating Software Usability, Ronan Fitzpatrick

Articles

This paper presents a usage analysis and taxonomy of methods which are used to evaluate the usability of computer systems. To accommodate the analysis and taxonomy, a matrix of strategies which can be used for effective usability evaluation is presented. Such an analysis, taxonomy and strategies support human-computer interaction (HCI) professionals who have the responsibility for ensuring computer system usability. The strategies outlined are named Virtual Engineering, Soft Modelling, Hard Review and Real World. This paper also uses a composite set of existing popular generic evaluation methods which can be used as part of these strategies. The methods used are …

Euroconstruction Report 1, Louis Gunnigan, Trevor Orr

Reports

This report was prepared on behalf of the Construction Industry Federation as Ireland’s initial contribution to the Leonardo da Vinci Project: Euroconstruction.

The report is divided into 3 sections.

Section 1 concentrates on the recent and likely future changes in the structure of the Irish construction market and the impact of these changes on project management and project financing. The recent growth of the industry is documented and predictions for the future of the industry in Ireland are summarised. The conclusions reached show that an increased involvement in the financing of public projects is required from the private sector if …

A Corba-Base Integration Of Distributed Electronic Healthcare Records Using The Synapses Approach, Jane Grimson, William Grimson, Damon Berry, Gaye Stephens, Eoghan Felton, Dipak Kalra, Pieter Toussaint, Onno Weir

Articles

The ability to exchange in a meaningful, secure, and simple fashion relevant healthcare data about patients is seen as vital in the context of efficient and cost-effective shared or team-based care. The electronic healthcare record (EHCR) lies at the heart of this information exchange, and it follows that there is an urgent need to address the ability to share EHCR's or parts of records between carers and across distributed health information systems. This paper presents the Synapses approach to sharing based on a standardized shared record, the Federated Healthcare Record, which is implemented in an open and flexible manner using …

Usable Software And It's Attributes: A Synthesis Of Software Quality: European Community Law And Human-Computer Interaction., Ronan Fitzpatrick, Catherine Higgins

Conference papers

Strategic managers and IS professionals who are responsible for specifying, acquiring and producing quality software products are not supported by the endless flow of new international standards, legislation and user requirements. In order to clarify the current situation for everybody concerned with software quality, and especially those interested in usability, there is a need for a new review and evaluation of the various strands that contribute to software quality. By way of review this paper recalls the original software quality factors which were defined twenty years ago by McCall et al. and presents a methodical analysis and synthesis of three …

White Light Interferometric Surface Profiler, Vincent Toal, Brian Bowe

Articles

We describe an optical system for 3-D profilometry based on the white light interferometer. We detail a simple way to construct a profiler that uses two simple algorithms which deal efficiently and quickly with the data. The system has a theoretically unlimited range and can deal with rough and smooth surfaces

Performance And Robustness Issues In The Compensation Of Folpd Processes With Pi And Pid Controllers, Aidan O'Dwyer

Conference papers

This paper will discuss the compensation of first order lag plus time delay (FOLPD) processes using PI and PID controllers whose parameters are specified using appropriate tuning rules. The gain margin, phase margin and maximum sensitivity of the compensated system as the ratio of time delay to time constant of the process varies, are used as ways of judging the performance and robustness of the system.

The Gain Scheduled Piece-Wise Adaptive Digital Control Of A Ph Process, Eugene O'Shaughnessy, Aidan O'Dwyer

Conference papers

The compensation of a pH process is complicated by the non-linear nature of the process titration curve and the significant time delays that typically exist in such processes. This paper will propose the use of a gain scheduled piecewise adaptive PI controller to compensate the process. A pilot plant is controlled, with the control algorithm implemented on a programmable controller. SCADA software displays and trends the plant and controller signals.

A Comparison Of Some Low Cost Laminates For Antennas Operating In The 2.45 Ghz Ism Band, Max Ammann

Conference papers

An evaluation of some low-cost laminates suitable for microstrip patch antennas is presented. Criteria for the selection of substrates for antenna fabrication are given careful consideration. A coaxial-probe fed linearly-polarized rectangular microstrip patch operating at a frequency of 2.45 GHz was fabricated on four different low cost laminates. The substrates used were polyester, epoxy glass (FR-4), a ceramic filled PTFE composite and a woven glass-reinforced hydrocarbon and ceramic thermoset material. Material properties are discussed and the antenna performances are evaluated and compared to one fabricated on a thick glass-loaded microfiber PTFE substrate. An evaluation of some inexpensive microstrip antenna CAD …

Bs News

Building Services Engineering

No abstract provided.

The Investigation Of The Relaxation Process In Antiferroelectric Liquid Crystals By Electro-Optic Spectroscopy, Yuri Panarin, O. Kalinovskaya, J.K. Vij

Articles

Electrooptic spectroscopy of an antiferroelectric liquid crystal is carried out over a range of frequencies from 1 Hz to 100 kHz. In the antiferroelectric SmCA phase two relaxation processes are found, one at the fundamental frequency of a mode and the second at twice the frequency of a different mode. A comparison of the results of the electro-optic spectroscopy with a theoretical study of the motion of the director of an antiferroelectric helix subject to a weak alternating field enables a determination of the origin of the relaxation processes in antiferroelectric phases. © 1998 American Institute of Physics.

The Development Of Electromechanical Batteries For Power System Support And For Short-Term Standby Power, Michael Peter O'Leary

Masters

The slow move from a fossil-fuel powered society to a renewable-energy powered society is creating and will continue to create a demand for good energy storage techniques. The electromechanical battery (EMB), comprising a flywheel energy storage system with electrical input and output, is one of the many candidate technologies. Two different EMB types are evaluated in this present project. The first is a ring (or annular) flywheel to be constructed using fibre composite materials and to rotate at high speed in a vacuum. Energy is to be imported and exported electromagnetically based on linear electrical machine principles. Confinement of the …

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

The Role Of Computer Simulation In The Context Of Zero-Emission Power Plants, Jim Mcgovern

Other resources

The role of computer simulation in the context of zero-emission power plants is outlined. The use of computer simulation models to simulate zero-emission power plants in fine detail is strongly recommended.

Anatomy Of A Strike: Waterford Glass 1990, Eddie Conlon

Conference papers

No abstract provided.

Observation And Investigation Of The Ferrielectric Subphase With High Qt Parameter, Yuri Panarin, O. Kalinovskaya, J.K. Vij, J.W. Goodby

Articles

Dielectric relaxation processes in an antiferroelectric liquid crystal (AFLC) have been investigated over a wide range of frequencies from 1 Hz to 1 GHz. The AFLC under investigation possesses a variety of different ferrielectric, ferroelectric, and antiferroelectric phases. Dielectric and polarization measurements under direct bias voltage have been made with a view to clarifying the origin of the high-temperature ferrielectric phase, which appears between the AF and smectic-C phases. This phase is assigned to an unstable ferrielectric phase with qT parameter greater than 1/2 (according to the Ising model) or a doubly modulated incommensurate phase (according to the expanded Landau …

The Down Survey Of Ireland, Frank Prendergast

Books/Book Chapters

No abstract provided.

The Short-Term Effects Of Mortars On Salt Movement In Stone, Simon H. Perry, Aidan Duffy

Articles

Salt-induced decay processes are one of the most important reasons for the decay of many stone buildings and monuments. This paper investigates the role played by masonry mortars in the movement of salts within Baumberger sandstone and Portland limestone. The methodology used involved the monitoring of stone units containing mortar joints which were exposed to a city-centre environment. Rain-water run-off was collected from the stone/mortar units during the exposure period; the units were subsequently destructively analysed. The methods of run-off and destructive sample analysis used included ion chromatography and atomic absorption spectrophotometry; stone and mortar samples were also analysed petrographically. …