Engineering Commons^™

A Simple Sol-Gel Processing For The Development Of High-Temperature Stable Photoactive Anatase Titania, Suresh Pillai, Declan Mccormack, John Colreavy

Articles

No abstract provided.

Experimental Study For The Conditions Of Analog Switching In Ferroelectric Liquid Crystal Cells, V. Manjuladevi, Yuri Panarin, J.K. Vij

Articles

The authors study the effect of the spontaneous polarization (PS) of a ferroelectric liquid crystal mixture with compensated helix and of the thickness of the alignment layer (da) on the analog switching in a cell. The quality of analog switching is established in terms of its contrast ratio, texture in the dark state, and the electrostatic energy. The latter approximates to PS 2da for da

Influence Of Electric Field And Light On An Easy Axis Of Nlc Confined By Rectangular Channel At Weak Surface Anchoring, S.V. Pasechnik, A.V. Dubtsov, Yuri Panarin, D.V. Shmeliova, V.A. Tsvetkov, V.G. Chigrinov

Articles

We present new experimental results on combined action of light and electric field on a nematic liquid crystal in a rectangular channel at a weak surface anchoring. The first experimental study of slow surface dynamics at combined action of electric field and polarized light in new experimental geometry was performed. Influence of polarized light on spatial twist-like deformation of a director field induced by electric field was established.

Discontinuous Change In The Smectic Layer Thickness In Ferrielectric Liquid Crystals, V. P. Panov, J. K. Vij, Yuri Panarin, C. Blanc, V. Lorman, J. W. Goodby

Articles

The temperature dependence of the thickness of thick free-standing films is studied using a high-resolution film thickness measurement technique. A small discontinuity in the temperature dependence of the smectic layer thickness at every phase transition between ferro-, ferri-, and antiferroelectric phases is observed. We show that the major contribution to it arises from a change in the smectic tilt angle.

Pure Non-Blocking Lc Based Matrix Optical Switch For All-Optical Fibre Networks, Yuri Panarin, V. Alex

Articles

New pure non-blocking matrix optical switch scheme for fiber networks is presented. The optical switch is based on conventional LCD technology, where the each pixel controls the polarization state of the light beam. The suggested switch offers several advantages over the conventional cross-point architecture such as: cost; complexity; size; adjustment; and optical performance

Optical Performance Of Non-Blocking 4x4 Optical Switch: Simulation And Experiment, V. Alex, A. Dubtsov, Yuri Panarin, T. Wilkinson

Articles

A prototype of pure non-blocking 4x4 optical LC switch was designed and built. This switch is based on conventional LCD technology, where the each pixel controlled the polarization state of the light beam. An addressing algorithm was described. The optical performance of the switch, such as cross-talk and insertion loss, was simulated and experimentally studied. The suggested approach offers several advantages over the conventional cross-point architecture such as: cost; complexity; size; adjustment; and optical performance.

Increasing Effectiveness Of Public Private Partnerships In The Irish Construction Industry, Louis Gunnigan

Doctoral

By 2003 the first Irish Public Private Partnership (PPP) projects had reached the operational stage. Media reports were emerging of significant differences in the effectiveness of these projects.

This research set out to find a means by which effectiveness of PPPs could be increased and to develop a model that would assist PPP practitioners with this task in the future. Through a literature review, the Irish PPP process was mapped, the changes encountered in the introduction of PPP were investigated and a conceptual model – based on a traditional process model - was proposed. The model was tested by examining …

Realising Electronic Tendering In The Irish Construction Industry, Alan V. Hore

Conference papers

No abstract provided.

Efficiency Gains To Be Won Through The Introduction Of Electronic Tendering In The Construction Industry, Alan V. Hore, Roger West

Conference papers

The tendering process predominantly adopted in the Irish construction industry is largely paper-dependent. However, the increase in the availability of high speed Information Communications Technology (ICT) has meant that construction consultants can disseminate this information more cost effectively in an electronic format. The aim of this paper is to present a status report on an industry-led network project currently being undertaken by the Construction Information Technology Alliance (CITA) in Ireland. This project aims to demonstrate how greater effectiveness and efficiency can be applied to the tendering process by the application of ICT already used widely in other industries. The status …

Citax: Defining Xml Standards For Data Exchange In The Construction Industry Supply Chain, Alan V. Hore, Roger West

Conference papers

The current methods of ordering, delivering and invoicing of products in the construction industry is enormously inefficient, with vast quantities of paperwork, duplication of effort, scanning, re-keying and resolving mismatches between invoices, delivery dockets and purchase orders. The purpose of this paper is to introduce the Construction IT Alliance eXchange (CITAX) project and, in particular, to outline the work carried out-to-date by a special interest group within the project. They are seeking to define a universal set of eXtensible Mark-Up Language (XML) message standards that will allow suppliers and contractors to exchange information with each other in supply chain activity. …

Dit Frequency Based Incremental Attribute Selection For Gre., John D. Kelleher

Conference papers

The DIT system uses an incremental greedy search to generate descriptions, (similar to the incremental algorithm described in (Dale and Reiter, 1995) ) incremental algorithm). The selection of the next attribute to be tested for inclusion in the description is ordered by the absolute frequency of each attribute in the training corpus. Attributes are selected in descending order of frequency (i.e. the attribute that occurred most frequently in the training corpus is selected first).

Mediating Between Qualitative And Quantitative Representations For Task-Orientated Human-Robot Interaction., Michael Brenner, John D. Kelleher, Nick Hawes, Jeremy Wyatt

Conference papers

In human-robot interaction (HRI) it is essential that the robot interprets and reacts to a human’s utterances in a manner that reflects their intended meaning. In this paper we present a collection of novel techniques that allow a robot to interpret and execute spoken commands describing manipulation goals involving qualitative spatial constraints (e.g. “put the red ball near the blue cube”). The resulting implemented system integrates computer vision, potential field models of spatial relationships, and action planning to mediate between the continuous real world, and discrete, qualitative representations used for symbolic reasoning.

Increasing Effectiveness Of Public Private Partnerships In The Irish Construction Industry, Louis Gunnigan

Doctoral

By 2003 the first Irish Public Private Partnership (PPP) projects had reached the operational stage. Media reports were emerging of significant differences in the effectiveness of these projects.

This research set out to find a means by which effectiveness of PPPs could be increased and to develop a model that would assist PPP practitioners with this task in the future. Through a literature review, the Irish PPP process was mapped, the changes encountered in the introduction of PPP were investigated and a conceptual model – based on a traditional process model - was proposed. The model was tested by examining …

Process Modelling Support For The Conceptual Modelling Phase Of A Simulation Project, Cathal Heavey, John Ryan

Conference papers

While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the conceptual modelling phase. Several authors have reported the advantages of using process modelling tools in the early phases of a simulation project.

This paper provides an overview of process modelling tools in relation to their support for simulation, categorizing the tools into formal method and descriptive methods. A conclusion from this review is that none of the tools available adequately support the requirements gathering phase of simulation. This is not surprising as none of the process modelling …

Bs News

Building Services Engineering

No abstract provided.

Application Of Advanced Computational Modelling In The Numerical Prediction Of The Haemodynamic Impact Of Coronary Stent Implantation, Jonathan Murphy, Fergal Boyle

Conference Papers

Coronary stent implantation can improve blood flow in an artery narrowed by the build up of arterial plaque. However, the haemodynamic effect of stent placement is unclear and may influence arterial restenosis (re-blockage). In this investigation the stent induced, non-Newtonian blood flow disturbances have been captured in a three dimensional computational domain. The results clearly show areas of low wall shear stress proximal and distal to the stent wires, a characteristic which is known to encourage restenosis. Furthermore, this computational method of observing the complex haemodynamics of the stent environment can be used in conjunction with medical trial data to …

Cop-On To The Risks Of Buying Abroad, Lorcan Sirr

Media

No abstract provided.

Experimental Investigation On Voip Performance And The Resource Utilization In 802.11b Wlans, Miroslaw Narbutt, Mark Davis

Conference papers

In a shared medium network like the 802.11b WLAN, predicting the quality of VoIP calls from the resource usage of the wireless medium is highly desirable. Analyzing the bandwidth usage at the L2/MAC layer may be especially useful for potential QoS provisioning and call admission schemes. This paper experimentally investigates the relationship between resource utilization in WLANS and the quality of VoIP calls transmitted over wireless medium. Specifically we evaluate how the amount of free bandwidth influences transmission impairments (i.e. delay, loss and jitter) and thus call quality. Resource utilization (under the MAC bandwidth components framework) is calculated by a …

Bs News

Building Services Engineering

No abstract provided.

Experimental Analysis Of An 802.11b Wireless Mesh Network, Brian Keegan, Karol Kowalik, Mark Davis

Conference papers

Wireless Mesh Networks (WMNs) are a type of radio-based network which require minimal configuration and infrastructure. They can be built using relatively low cost radio and computing platforms. In this paper we attempt to analyze the performance of a simple WNM using various packet sizes as well as a multi-hop WMN.

Textual Case-Based Reasoning For Spam Filtering: A Comparison Of Feature-Based And Feature-Free Approaches, Sarah Jane Delany, Derek Bridge

Articles

Spam filtering is a text classification task to which Case-Based Reasoning (CBR) has been successfully applied. We describe the ECUE system, which classifies emails using a feature-based form of textual CBR. Then, we describe an alternative way to compute the distances between cases in a feature-free fashion, using a distance measure based on text compression. This distance measure has the advantages of having no set-up costs and being resilient to concept drift. We report an empirical comparison, which shows the feature-free approach to be more accurate than the feature-based system. These results are fairly robust over different compression algorithms in …

Experimental Investigation Of The Effects Of Background Traffic Loads On Streamed Video Over 802.11b Wlans, Tanmoy Debnath, Nicola Cranley, Mark Davis

Conference papers

Video is a frame based media and video streaming is often described as “bursty” which has a large impact on the Quality of Service of the video streaming application over WLAN networks. In this paper the impact of background load on the performance of streaming MPEG-4 video with a video server located on the wired network streaming to wireless client is analysed. We experimentally investigate the performance for both uplink and downlink loads. The performance is measured in terms of the key parameters of bit rate, loss rate and mean delay since these are the primary factors that affect the …

Bs News

Building Services Engineering

No abstract provided.

Performance Of A Variable Speed Double-Fed Induction Generator Wind Turbine During Network Voltage Unbalance Conditions, Joseph Kearney, Michael Conlon

Conference papers

The issues of the negative performance of DFIG’s due to supply network voltage unbalance are outlined in this paper. The paper shows the effects that voltage unbalance can have on a DFIG, using the power simulation program DigSilent. The results from simulations show that voltage unbalance affects the both the induction generator and the rotor converter, due to the high unbalanced currents generated. The ability to modify the control strategy of a DFIG to compensate for voltage unbalance is outlined and a proposal to build a test-rig suitable to implement such a system is suggested.

The Effects Of Background Traffic On The End-To-End Delay For Video Streaming Applications Over Ieee 802.11b Wlan Networks, Nicola Cranley, Mark Davis

Conference papers

The bursty nature of video streaming applications is due to the frame-based structure of video and this has an important impact on the resource requirements of the WLAN, affecting its ability to provide Quality of Service (QoS) particularly under heavily loaded conditions. In this paper we analyse this bursty behaviour in depth. We show how each video frame is queued at the AP causing the packet delay to vary in a sawtooth manner that is related to the frame rate, the number of packets per video frame, and the packet size. We infer the maximum background traffic load that can …

Bs News

Building Services Engineering

No abstract provided.

Technology Influences On Small Logistics Providers: A Case Study Analysis, Pietro Evangelista, Alan Mckinnon, Edward Sweeney

Conference papers

ICT has triggered many changes in the logistics service industry. New technology is reshaping the organisation and structure of this industry as ICT impacts significantly on the operations of 3PLs. Within this process, while large 3PLs are gaining substantial benefits from technology usage, the nature of changes resulting from ICT usage in small 3PLs remains unclear. This is critical particularly for those markets populated by a high number of small 3PLs such as the Italian logistics industry. From the research point of view, there is still a gap in the literature where the role of technological capability in small 3PLs …

Outsourcing In Ireland: A Literature Review And Survey Perspective To Construct An Outsourcing Roadmap, Aoife O'Riordan, Edward Sweeney

Conference papers

This paper investigates what is happening in Ireland at the moment regards outsourcing. It looks into the literature review and the survey conducted. The research took place over a period of two years, initially as a literature review, and then the survey was conducted through the mediums of e-mail and the postal service. The survey analysis found that Ireland was the most likely place for Irish companies to outsource to, and that nearly 40 percent of the companies that have been surveyed have started on their latest outsourcing initiative since 2004. This indicates that outsourcing is still important on the …

Modeling Liquid-Crystal Devices With The Three-Dimensional Full-Vector Beam Propagation Method, Qian Wang, Gerald Farrell, Yuliya Semenova

Articles

Simulation of light propagation within nematic liquid-crystal (LC) devices is considered, of which the director is aligned normal to the z axis. A three-dimensional full-vector finite-difference beam propagation method for an anisotropic medium is presented and an alternating direction implicit scheme is adopted. Simulations of light propagation in a bulk polarization converter, a waveguide with a LC covering layer, and an integrated polarization splitter and optical switch are presented. Comparison with an existing simulation method is carried out for beam behavior within the bulk polarization converter. The effect of strong surface anchoring of a LC cell on the beam behaviors …

Moving A Part-Time Engineering Course To A Student-Centred Paradigm, Kevin Kelly

Conference papers

This paper is a further reflection on two conference papers presented at the World Conference for Continuing Engineering Education (WCCEE) in Vienna in April 2006 and National University of Ireland (NUI) Galway Conference: The Challenge of Diversity: Teaching, Support and Student Learning , June 2006. Both conference papers dealt with different aspects of my experiences of the theoretical and pedagogical changes required in re-design and delivery of a part-time engineering programme for the continuing education development of electrical engineers in the workforce.