Engineering Commons^™

The Design Of A Modelling, Monitoring And Validation Method For A Solid Wall Structure, Timothy O'Leary, Gillian Menzies, Aidan Duffy

Conference Papers

Hygrothermal assessment is the combined analysis of heat, air and moisture transfer through the building fabric. The two approaches are covered by conventions known as the IS EN 5250:2011 (Glaser method) and IS EN 15026:2007 which differs from Glaser by solving the equations numerically using computer software. Results for hygrothermal analysis provide valuable information for surface and interstitial condensation risk assessment and the impact of energy upgrades. For traditional solid walled structures, conditions such as wind driven rain (WDR) and rising ground water can have a significant impact on the environmental behaviour and in particular the moisture behaviour of the …

The Influence Of Particle Content On The Equi-Biaxial Fatigue Behaviour Of Magnetorheological Elastomers, Yanfen Zhou, Stephen Jerrams, Tony Betts, Gerald Farrell, Lin Chen

Articles

The equi-biaxial fatigue behaviour of silicone based magnetorheological elastomers (MREs) with various volume fractions of carbonyl iron particles ranging between 15% and 35% was studied. Wöhler curves for each material were derived by cycling test samples to failure over a range of stress amplitudes. Changes in complex modulus (E*) and dynamic stored energy during the fatigue process were observed. As for other elastic solids, fatigue resistance of MREs with different particle contents was shown to be dependent on the stress amplitudes applied. MREs with low particle content showed the highest fatigue life at high stress amplitudes while MREs with high …

Designing The Identities Of Engineers, Mike Murphy, Shannon Chance, Eddie Conlon

Books/Book chapters

Book Chapter forthcoming in Engineering Education and Practice in Context, Vol. 2 to be published by Springer in 2015.

First Steps In Developing Cement-Based Batteries To Power Cathodic Protection Of Embedded Steel In Concrete, Niall Holmes, Aimee Byrne, Brian Norton

Articles

This paper presents the first steps in developing innovative cement-based batteries to power cathodic protection in reinforced concrete structures. Initial electrical outputs of 1.55V and 23mA have been found to be sufficient to polarise prescribed corrosion currents of 20mA per m2 of embedded steel. Cathodic protection is a well-developed and powerful technique to limit the effects of steel reinforcement corrosion. However, as it requires an electrical supply day and night, it is often powered by non-environmentally friendly diesel generators or connected to the electrical grid. This paper focuses on increasing the ionic conductivity of the solution in the cement pores, …

Energy Savings Across Eu Domestic Building Stock By Optimizing Hydraulic Distribution In Domestic Space Heating Systems, Ciara Ahern, Brian Norton

Articles

The objective of this work is to quantify the resultant savings across the EU from the optimization of existing system components in domestic space heating distribution systems to maintain comfort levels. Heat energy savings are shown to range from 1% to 19% depending on dwelling type, age, location and initial specific heat energy consumption.

Introducing Pbl Into Civil And Structural Engineering, Niall Holmes, Una Beagon

Teaching Fellowships

The benefits of problem based learning for students are a deeper understanding of lecture material, and the development of problem solving and collaboration skills which will greatly enhance their educational experience. This approach has been successful in other programmes as it departs from the traditional ‘what I am told I need to know’ to ‘what I need to know to solve the problem’ promoting self-directed learning. Lecturers in turn transition from the giver of information to the facilitator of learning through support, guidance and monitoring. This project introduced an active learning element into two concrete technology modules by replacing traditional …

A Critical Realist Approach To Engineering Ethics, Eddie Conlon

Conference papers

This paper is focused on the teaching of engineering ethics (EE). Through a focus on safety and the lens of what sociologists call the agency/ structure relationship it examimes various approaches to this teaching. Drawing on Critical Realism it argues there are deficiencies in both the dominant approach and a number of proposed alternatives as they suffer from various forms of conflationism . By drawing on Critical Realism (CR) a more robust agenda for teaching engineering ethics can be developed. It is argued that CR offers a basis for understanding the range of factors which lead to accidents and disasters. …

Visqol: An Objective Speech Quality Model, Andrew Hines, J. Skoglund, A. C. Kokaram, N. Harte

Articles

This paper presents an objective speech quality model, ViSQOL, the Virtual Speech Quality Objective Listener. It is a signal-based, full-reference, intrusive metric that models human speech quality perception using a spectro-temporal measure of similarity between a reference and a test speech signal. The metric has been particularly designed to be robust for quality issues associated with Voice over IP (VoIP) transmission. This paper describes the algorithm and compares the quality predictions with the ITU-T standard metrics PESQ and POLQA for common problems in VoIP: clock drift, associated time warping, and playout delays. The results indicate that ViSQOL and POLQA significantly …

Occurrence Of Five Different Orthogonal Smectic Phases In A Bent-Core (Bc) Liquid Crystal, S. Sreenilayam, Yuri Panarin, J. K. Vij, A. Lehmann, C. Tschierske

Articles

Five orthogonal smectic phases (Sm-A, Sm-Ab, Sm-APR, Sm-APAR, and Sm-APA) were observed in a 4-cyanoresorcinol bisbenzoate with twoterephthalate–based wings achiral bent-core(BC) compound. The phase behavior was investigated by polarising optical microscopy, second harmonic electro-optic response(EO2) and dielectric spectroscopy. The field dependent biaxiality of polar and non-polar Sm-A phases was studied. It is obviously of enormous scientific significance and practical interest to find five different orthogonal smectic phases in a low molecular weight bent-core (BC) compound at relatively low temperatures.

Dit-Topcon Internship Experience, Audrey Martin, Abigail Iversen

Articles

The Technological University Dublin (DIT: http://www.dit.ie/) is one of the largest Higher Education Institutes in Ireland, with 20,000 students registered and over 2000 members of staff. It has been providing technological higher education for over one hundred and twenty years encompassing the full spectrum of Third Level programmes. During that time the Institute's alumni have played important roles in technical and scientific innovation, economic and social development and culture and education both in Ireland and internationally.

The CEO of Topcon Positioning Systems Inc., Ray O’Connor is a DIT School of Surveying alumnus and in October 2013 Ray visited his …

An Architectural Perspective On Structured Sacred Space—Recent Evidence From Iron Age Ireland, Frank Prendergast

Book/Book Chapter

N/A

A Knowledge-Driven Distributed Architecture For Context-Aware Systems, Dennis Lupiana

Doctoral

As the number of devices increases, it becomes a challenge for the users to use them effectively. This is more challenging when the majority of these devices are mobile. The users and their devices enter and leave different environments where different settings and computing needs may be required. To effectively use these devices in such environments means to constantly be aware of their whereabouts, functionalities and desirable working conditions. This is impractical and hence it is imperative to increase seamless interactions between the users and devices,and to make these devices less intrusive. To address these problems, various responsive computing systems, …

Development Of A Methodology For Assessing Safety & Operational Reporting Within Safety Critical Industries, Maria Chiara Leva, Ewan Douglas, Sam Cromie

Articles

Develop a best-practice model based on literature and industrial experience

• Industrial Case Studies to allow a cross industrial comparison

• Develop a suite of techniques that can be used cross-industry to assess the effectiveness of a reporting system

• Propose a theoretical framework for the effective implementation of risk and hazard reporting as an input for safety management

Visqolaudio: An Objective Audio Quality Metric For Low Bitrate Codecs, Andrew Hines, Eoin Gillen, Damien Kelly, Jan Skoglund, Anil Kokaram, Naomi Harte

Articles

Streaming services seek to optimise their use of bandwidth across audio and visual channels to maximise the quality of experience for users. This letter evaluates whether objective quality metrics can predict the audio quality for music encoded at low bitrates by comparing objective predictions with results from listener tests. Three objective metrics were benchmarked: PEAQ, POLQA, and VISQOLAudio. The results demonstrate objective metrics designed for speech quality assessment have a strong potential for quality assessment of low bitrate audio codecs.

An Analysis Of The Impact Of Playout Delay Adjustments Introduced By Voip Jitter Buffers On Listening Speech Quality, Peter Počta, Hugh Melvin, Andrew Hines

Articles

This paper investigates the impact of frequent and small playout delay adjustments (time-shifting) of 30 ms or less introduced to silence periods by Voice over IP (VoIP) jitter buffer strategies on listening quality perceived by the end user. In particular, the quality impact is assessed using both a subjective method (quality scores obtained from subjective listening test) and an objective method based on perceptual modelling. Two different objective methods are used, PESQ (Perceptual Evaluation of Speech Quality, ITU-T Recommendation P.862) and POLQA (Perceptual Objective Listening Quality Assessment, ITU-T Recommendation P.863). Moreover, the relative accuracy of both objective models is assessed …

Tcd-Voip, A Research Database Of Degraded Speech For Assessing Quality In Voip Applications, Andrew Hines, Naomi Harte, Eoin Gillen

Conference papers

There are many types of degradation which can occur in Voice over IP calls. Degradations which occur independently of the codec, hardware, or network in use are the focus of this paper. The development of new quality metrics for modern communication systems depends heavily on the availability of suitable test and development data with subjective quality scores. A new dataset of VoIP degradations (TCD-VoIP) has been created and is presented in this paper. The dataset contains speech samples with a range of common VoIP degradations, and the corresponding set of subjective opinion scores from 24 listeners The dataset is publicly …

On A New Method For Interior Lighting Design, James Duff

Doctoral

In 2009, Christopher Cuttle began to challenge the suitability of the metrics contained within current lighting design standards and guidance. In short, Cuttle proposed a move away from providing an amount of light that relates to the difficulty of a visual task and instead, providing an amount of light that relates to the brightness of a space. This sense of brightness would be estimated by a new lighting metric, Mean Room Surface Exitance. The research presented in this thesis strove to examine, critically evaluate, analyse and investigate the merit of changing indoor lighting standards to include Mean Room Surface Exitance. …

Enhanced Quality Of Experience Based On Enriched Network Centric And Access Control Mechanisms, Andreas Roos

Doctoral

In the digital world service provisioning in user satisfying quality has become the goal of any content or network provider. Besides having satisfied and therefore, loyal users, the creation of sustainable revenue streams is the most important issue for network operators [1], [2], [3]. The motivation of this work is to enhance the quality of experience of users when they connect to the Internet, request application services as well as to maintain full service when these users are on the move in WLAN based access networks. In this context, the aspect of additional revenue creation for network operators is considered …

A Study Of The Impact Of Various Geometric Factors On The Capacity Of Short Range Indoor Mimo Communications Channels, Anthony Grennan

Doctoral

MIMO antenna array systems have been proposed as a means of increasing the spectral efficiency of wireless systems. However, their performance is likely to be sub-optimal if typical uniform antenna array structures are arbitrarily positioned; as they depend on spatial multiplexing. This is particularly true for indoor environments in which transmission ranges are short resulting in a strong correlation of the main propagation paths, especially the line-of-sight components. This makes it difficult to achieve successful spatial multiplexing which depends on a decorrelated set of signal components. Thus, the physical propagation channel and geometry of the antenna arrays, especially the inter-element …

Development Of The Framework For A Self-Assessment Tool To Assess The Effectiveness Of Reporting Within A Safety Critical Industry, Maria Chiara Leva, Samuel Cromie, Ewan Douglas

Conference papers

There is currently a large amount of literature to provide guidance on the areas that should be considered when developing a reporting system. However there is no current methodology of monitoring the performance and compliance of a reporting system.This paper outlines the development process for a Self-Assessment Tool (SAT) assessing the effectiveness of safety reporting within safety critical activities. The paper outlines the need for such a self-assessment tool, the areas that will be assessed (and the rationale be-hind their selection), selection of the platform and finally the planned validation exercises for the paper

The Identification Of Assessment Criteria For A Safety Reporting Self-Assessment Tool, Maria Chiara Leva, Samuel Cromie, Ewan Douglas

Conference papers

This paper describes the assessment criteria that have been identified for use within a self-assessment tool for risk reporting within an industrial context. An in-depth review of the available literature was carried out exposing the criteria discussed within this paper. The criteria target all areas of reporting from the design of the reporting interface to the cultural considerations and initiatives. These criteria will be refined and weighted using industrial case study experience and then developed into the full self-assessment tool.

Computer Hardware: Hardware Components And Internal Pc Connections, Jerome Casey

Instructional Guides

No abstract provided.

Computer Hardware: Building A High Spec Desktop For Gaming, Jerome Casey

Instructional Guides

No abstract provided.

Spatial Brightness, Horizontal Illuminance And Mean Room Surface Exitance In A Lighting Booth, James Duff, Kevin Kelly, C. Cuttle

Articles

This paper presents a pilot study that has investigated the suitability of mean room surface exitance as a predictor of spatial brightness and compared these results with how horizontal illuminance predicts spatial brightness under the same conditions. The experiment took a group of 26 participants and, using a scaled booth, exposed each participant to three levels of mean room surface exitance, each delivered with three different light distributions and three different surface reflectances, resulting in a total of 27 light scenes. Results demonstrated that, under the range of conditions to which participants were exposed, a systematic relationship existed between mean …

Dielectric Study Of Liquid Crystals With Large Electroclinic Effect, O. E. Panarina, Yuri Panarin, J. K. Vij

Articles

Here we report results of the study of tilt angle and birefringence of some “high-electroclinic” materials having similar molecular structure with two and three siloxane spacers. The structure of these LC materials were studied by dielectric spectroscopy, birefringence and tilt angle measurements. Three of the four studied materials with a siloxane fragment are the deVries materials, but the siloxane-free sample is conventional SmA phase and is thus different. Possible models for the molecular structures of deVries SmA∗ phases are discussed.

Flexoelectric Behaiour Of A Bimesogenic Liquid Crystal, R. Balachandran, V. P. Panov, Yuri Panarin, M. G. Tamba, G. H. Mehl, J. K. Song, J. K. Vij

Articles

The effective flexoelectric coefficient and flexoelectric polarization are investigated for a bimesogenic liquid crystal CBC11CB with a twist bend nematic phase (Ntb). The effective flexoelectric coefficients for CBC11CB in the ordinary nematic phase (N) are obtained to be much larger in comparison to conventional calamitics, and is almost twice higher for CBC11CB than that reported for another odd symmetric bimesogen. The flexoelectric polarization (Pf) in the N phase is found to be almost 2.5 times higher than in rod-like molecules. Additionally, Pf is obtained to be much larger in the Ntb phase than in the nematic phase

Flexoelectric Polarization Studies In Bent-Core Nematic Liquid Crystals, S. Sreenilayam, Yuri Panarin, J. K. Vij, S. I. Torgova, A. Lehmann, C. Tschierske

Articles

The flexoelectric polarization (Pf) of four bent-core nematic liquid crystals (LCs) has been measured using the pyroelectric effect. Hybrid aligned nematic cells are fabricated for measuring the pyroelectric response over the entire range of the nematic phase. It is found that the magnitude of flexoelectric polarization Pf and the sum of the flexoelectric coefficients |e1 +e3| for the bent-core LCs studied here are three to six times higher than for the calamitics. Pf is found to depend on the transverse dipole moment of LC molecules. However,|e1 +e3| values are by no means giant as |e3| alone had been reported for …

Dielectric Study Of Nematic Lc Built With Bent-Core Molecules, S. Sreenilayam, Yuri Panarin, J. K. Vij

Articles

Here we report results of the study of bent-core (BC) cybotactic nematic LC by dielectric spectroscopy and electro-optic measurements. In the absence of electric field, this material is uniaxial and exhibits only one relaxation process corresponding to the fluctuations of the polar clusters. The application of the external electric field induces biaxialityandthesecondrelaxationprocessappearsinthedielectricspectra.Thisisassigned to the collective mode. Possible models for cluster transformation under electric field are discussed.

Control Strategy And Hardware Implementation For Dc–Dc Boost Power Circuit Based On Proportional–Integral Compensator For High Voltage Application, Sanjeevikumar Padmanaban, Ersan Kabalci, Atif Iqbal, Haitham Abu-Rub, Olorunfemi Ojo

Articles

For high-voltage (HV) applications, the designers mostly prefer the classical DCeDC boost converter. However, it lacks due to the limitation of the output voltage by the gain transfer ratio, decreased efficiency and its requirement of two sensors for feedback signals, which creates complex control scheme with increased overall cost. Furthermore, the output voltage and efficiency are reduced due to the selfparasitic behavior of power circuit components. To overcome these drawbacks, this manuscript provides, the theoretical development and hardware implementation of DCeDC step-up (boost) power converter circuit for obtaining extra output-voltage high-performance. The proposed circuit substantially improves the high output-voltage by …

Integration Of Qos Metrics, Rules And Semantic Uplift For Advanced Iptv Monitoring, Ruairí De Fréin, Cristian Olariu, Yuqian Song, Rob Brennan, Patrick Mcdonagh, Adriana Hava, Christina Thorpe, John Murphy, Liam Murphy, Paul French

Articles

Increasing and variable traffic demands due to triple play services pose significant Internet Protocol Television (IPTV) resource management challenges for service providers. Managing subscriber expectations via consolidated IPTV quality reporting will play a crucial role in guaranteeing return-on-investment for players in the increasingly competitive IPTV delivery ecosystem. We propose a fault diagnosis and problem isolation solution that addresses the IPTV monitoring challenge and recommends problem-specific remedial action. IPTV delivery-specific metrics are collected at various points in the delivery topology, the residential gateway and the Digital Subscriber Line Access Multiplexer through to the video Head-End. They are then pre-processed using new …