Engineering Commons^™

The Application Of Learning Skills In An Engineering Programme, Leslie Shoemaker

Conference papers

At the Dublin Institute of Technology, an engineering programme in the School of Control Systems and Electrical Engineering has successfully incorporated a study skills module into the core curriculum. The module, titled Academic Development and Key Skills, is part of the first year of the programme and has a two-fold purpose. Primarily the goal is to assist the students with the transition from second level education to third level by teaching them a more competent learning style. This, in turn, helps to create a positive impact with respect to the retention of this student group within the programme. The second …

Study Of Same-Lane And Inter-Lane Gvw Correlation, Colin C. Caprani, Bernard Enright, E. J. O'Brien

Conference papers

Extensive work has been done over the last two decades on the simulation of traffic loading on bridges. The methodology used is to generate a number of years of simulated traffic and to use extreme value statistics to predict more accurately the characteristic loading for a given bridge. The parameters and probability distributions used in the Monte Carlo simulation must be based on observed sample traffic data. Some previous studies have made unsubstantiated assumptions regarding correlation between the Gross Vehicle Weights (GVW) of trucks in the same lane, or between trucks in adjacent, same direction lanes. For this paper, an …

Finding The Distribution Of Bridge Lifetime Load Effect By Predictive Likelihood, Colin C. Caprani, E. J. O'Brien

Conference papers

To assess the safety of an existing bridge, the loads to which it may be subject in its lifetime are required. Statistical analysis is used to extrapolate a sample of load effect values from the simulation period to the required design period. Complex statistical methods are often used and the end result is usually a single value of characteristic load effect. Such a deterministic result is at odds with the underlying stochastic nature of the problem. In this paper, predictive likelihood is shown to be a method by which the distribution of the lifetime extreme load effect may be determined. …

Bs News

Building Services Engineering

No abstract provided.

The Effect Of Physiological Cyclic Stretch On The Cell Morphology, Cell Orientation And Protein Expression Of Endothelial Cells, V. Barron, Claire Brougham, K. Coghlan, C. Stenson-Cox, D. O'Mahoney, P.E. Mchugh

Articles

In vivo, endothelial cells are constantly exposed to pulsatile shear and tensile stresses. The main aim of this study was to design and build a physiological simulator, which reproduced homogenous strain profiles of the tensile strain experienced in vivo, and to investigate the effect of this cyclic tensile strain on the cell morphology, cell orientation and protein expression of endothelial cells. The biological response of human umbilical vein endothelial cells to a uniaxial cyclic stretch, in this newly developed simulator, was examined experimentally using immunohistostaining and confocal imaging and it was

found that the cells elongated and oriented at 58.9± …

Exchange Faculty Perspectives On International Collaborations, Donal Mchale

Conference Papers

The main purpose of the paper is to document key issues in developing successful transatlantic faculty exchanges and to document perspectives and key learnings’ emanating from the development and implementation of an international exchange process.

Gauging Voip Call Quality From 802.11 Wlan Resource Usage, Miroslaw Narbutt, Mark Davis

Conference papers

In this paper we experimentally study the relationship between resource utilization in the wireless LAN and the quality of VoIP calls transmitted over the wireless medium. Specifically we evaluate how its overall capacity is shared between three basic MAC bandwidth components (load, access and free) as the number of VoIP calls increases and how it influences transmission impairments (delay, loss and jitter) and thus call quality. Resource utilization (under the MAC bandwidth components framework) is calculated by a WLAN probe application that passively “sniffs” packets at the L2/MAC layer of the wireless medium and analyses their headers and temporal characteristics. …

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

Conference papers

In this paper we present the results from an experimental study of the call capacity of an IEEE 802.11b network when using VoIP telephony. Experiments include increasing the number of VoIP users in a wireless test-bed and increasing the level of background traffic until network saturation occurs. The experiments allow us to perform an analysis of the access point (AP) buffer dynamics. Results show that the network is capable of supporting up to 16 VoIP stations (STAs). Due to the operation of the IEEE 802.11 medium access control (MAC) mechanism, the AP acts as a bottleneck for all traffic destined …

Effect Of Free Bandwidth On Voip Performance In 802.11b Wlan Networks, Miroslaw Narbutt, Mark Davis

Conference papers

In this paper we experimentally study the relationship between bandwidth utilization in the wireless LAN and the quality of VoIP calls transmitted over the wireless medium. Specifically we evaluate how the amount of free bandwidth decreases as the number of calls increases and how this influences transmission impairments (i.e. delay, loss and jitter) and thus degrades call quality. We show that the amount of free bandwidth is a good indicator for predicting VoIP call quality.

Low-Cost Wavelength Measurement Based On A Macrobending Single-Mode Fiber, Qian Wang, Gerald Farrell, Thomas Freir, Ginu Rajan, Pengfei Wang

Articles

A low-cost all-fiber wavelength measurement technique is proposed and demonstrated. A macrobending standard single-mode fiber is developed as an edge filter with an optimal design and simple surface processing. A ratiometric wavelength measurement system employing the developed macrobending fiber filter demonstrates a resolution of ∼10 pm in a wavelength range from 1500 to 1560 nm with ease of assembly and calibration.

The Impact Of Tcp Sliding Window On The Performance Of Ieee 802.11 Wlans, Enrique Roques Gomez, Mark Davis

Conference papers

In this paper the TCP sliding window mechanism is experimentally investigated as one of the possible causes of the unfairness often observed as IEEE802.11 wireless LANs. We show how by appropriately sizing the sliding window it is possible to re-introduce fairness into the operation of the WLAN.

Bs News

Building Services Engineering

No abstract provided.

Preliminary Results For A Monocular Marker-Free Gait Measurement System, Jane Courtney, Annraoi Depaor

Articles

This paper presents results from a novel monocular marker-free gait measurement system. The system was designed for physical and occupational therapists to monitor the progress of patients through therapy. It is based on a novel human motion capture method derived from model-based tracking. Testing is performed on two monocular, sagittal-view, sample gait videos – one with both the environment and the subject’s appearance and movement restricted and one in a natural environment with unrestricted clothing and motion. Results of the modelling, tracking and analysis stages are presented along with standard gait graphs and parameters.

A New Eccentric Geomagnetic Dipole To Give The Correct Dip Pole Locations, Annraoi De Paor, Ted Burke

Articles

In this paper, we describe a new eccentric dipole model of the Earth’s magnetic field. The constraints under which the conventional eccentric dipole model is defined result in predicted dip pole locations that differ significantly from the measured locations. Here, we give a preliminary exposition of a new dipole model which, because it is constrained by the observed dip pole locations, overcomes this problem.

The Computerised Design Of Prestressed Cncrete Slabs, Ronan Hogan

Masters

This thesis was aimed at the development of a finite element based software package for the analysis and design of prestressed concrete slabs. Many of the existing packages used in this area carry out a simplified two dimensional analysis of the slab which does not account for the secondary stresses set up by the presence of openings and notches in the slab. In an attempt to overcome this particular weakness, a finite element analysis package was written to help produce a more rigorous analysis of the stresses developed in prestressed concrete. The aims of the research were the examination of …

Bs News

Building Services Engineering

No abstract provided.

Thermal Performance Of Low Approach Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn

Conference Papers

Meteorological enthalpy analysis of temperate and maritime climates above 45˚N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary "high temperature" building cooling systems - such as chilled ceilings. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues a test rig, based on an open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed at DIT. A combination of experimental measurement and analysis is used in the investigations. …

Solar Energy Conversion Through Seaweed Photosynthesis With Combustion In A Zero-Emission Power Plant, Evgeny Yantovski, Jim Mcgovern

Other resources

A proposed ‘closed cycle’ power plant scheme, referred to as SOFT (Solar Oxygen Fuel Turbine), is described. The scheme involves the cultivation of macroalgae in a pond, combustion of their organic matter in a fluidised bed boiler that generates steam for a Rankine cycle steam power plant and the return of the combustion products to the pond to feed the algae. Oxygen, equivalent to that used for combustion, is re-released to the atmosphere by photosynthesis, while the carbon dioxide that is produced by combustion is absorbed by photosynthesis and thereby recycled. It is proposed that the seaweed Ulva, which is …

Resource And Technology Issues: Case Studies, Mike Murphy

Presentations

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Integrated Antenna For Multiband Multi-National Wireless Combined With Gsm1800/Pcs1900/Imt2000 + Extension, Matthias John, Max Ammann

Articles

A printed triple-band monopole antenna appropriate for use as a terminal antenna in modern wireless multiband systems is proposed. The impedance bandwidth of each band has been optimised using a quasi-Newton technique and the bandwidth includes virtually all wireless bands. Various parameter sweeps are presented which improve our understanding of the antenna, in particular, the effect of groundplane-size and branch-off point on impedance bandwidth and radiation pattern.

Using Case-Based Reasoning For Spam Filtering, Sarah Jane Delany

Doctoral

pam is a universal problem with which everyone is familiar. Figures published in 2005 state that about 75% of all email sent today is spam. In spite of significant new legal and technical approaches to combat it, spam remains a big problem that is costing companies meaningful amounts of money in lost productivity, clogged email systems, bandwidth and technical support. A number of approaches are used to combat spam including legislative measures, authentication approaches and email filtering. The most common filtering technique is content-based filtering which uses the actual text of the message to determine whether it is spam or …

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Indentation Fracture Of Bovine Cortical Bone: Acoustic Emission Technique, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

Indentation cutting may result in microcracking and main crack growth which was previously reported. In this study, we recorded the AE signals produced by cracking processes during cutting on cortical bone, measuring the cutting force and correlating between load-displacement curves and AE activities.

Cutting Rate Effect On Temperature During Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack

Conference Papers

When bone is cut the occurrence of thermal damage to the bone is of major concern to the surgeon. If the temperature exceeds 44°C for longer than 1 min, bone repair is impaired (Eriksson et al, 1984) and necrosis may occur. Repeated use of cutting blades may reduce the cutting efficiency (Wevers et al, 1987; Toksvig-Larsen et al, 1992). Wevers et al also found that there is a greater force required to cut cortical bone using a blunt saw compared to new one.

Low-Cost Wavelength Measurement Based On A Macrobending Single-Mode Fiber, Qian Wang, Gerald Farrell, Thomas Freir, Ginu Rajan, Pengfei Wang

Articles

A low-cost all-fiber wavelength measurement technique is proposed and demonstrated. A macrobending standard single-mode fiber is developed as an edge filter with an optimal design and simple surface processing. A ratiometric wavelength measurement system employing the developed macrobending fiber filter demonstrates a resolution of∼10 pmin a wavelength range from1500to1560 nmwith ease of assembly and calibration.

Design Of Integrated Polarization Beam Splitter With Liquid Crystal, Qian Wang, Gerald Farrell, Yuliya Semenova

Articles

An integrated polarization beam splitter based on a directional coupler (DC) with an etched slot and filled-in liquid crystal covering layer, which utilizes the birefringence of liquid crystal materials, is proposed. A supermode solution for the DC involving birefringence materials and the corresponding full-vector anisotropic beam propagation method are employed as modeling tools. A numerical design of the proposed structure is presented. Beam propagation behavior along the whole structure involving curved input and output regions and central coupling region is simulated. Simulation result shows an extinction ratio of 25.3 and 41.9 dB for the TE and TM mode, respectively.

Planar Antennas, Zhi Ning Cheng, Max Ammann, Xianming Qing, Xuan Hui Wu, T. S.P. See, A. Cai

Articles

This article reviews the state of the art in broadband antennas for emerging UWB applications and addresses the important issues of the broadband antenna design for UWB applications. First, a variety of planar monopoles with finite ground planes are reviewed. Next, the roll antennas with enhanced radiation performance are outlined. After that, the planar antennas printed on PCBs are described. A directional antipodal Vivaldi antenna is also presented for UWB applications. Last, a UWB antenna for wearable applications is exemplified

A Numerical Acoustic Fluid-Structure Simulation Of Therapeutic Ultrasound Angioplasty, Graham Gavin, Finbar Dolan, M.S J. Hashmi, Garrett Mcguinness

Conference Papers

INTRODUCTION Therapeutic ultrasound angioplasty is the delivery of high amplitude ultrasonic displacements to the distal-tip of small diameter wire waveguides with the goal of disrupting atherosclerotic plaques. This is a minimally invasive procedure that may have potential' in the treatment of complicated chronic total occlusions. The disruption of plaque is due to direct contact ablation and also cavitation, pressure waves and acoustic streaming in the fluid surrounding the vibrating waveguide distal-tip [1]. Cavitation appears to play a major role and some authors have suggested that plaque ablation is only evident above the cavitation threshold [2]. Makin and Everbach [3] performed …