Engineering Commons^™

Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann

Articles

Full duplex radios have become a topic of increased interest in the wireless communications community. As part of this development, many efforts were directed to passively decrease the self-interference level at the antenna outputs. However, in many proposed solutions transmission and reception occur through different propagation channels. This paper demonstrates and quantifies the negative impact of channel differentiation on pivotal applications of full-duplex radio, such as cognitive radio. Antenna designs used for self-interference suppression in full-duplex radio architectures are analyzed. In order to ensure that transmission and reception occur within the same propagation channel, the use of the envelope correlation …

The Acquisition Of Knowledge And Expertise In Construction: Understanding Construction Professionals, Lloyd Scott, Sittimont Kanjanabootra

Conference papers

Education programs these days especially in Construction Management have been designed and updated to response to market and stakeholder needs. However, there still exists a need for educators to understand how construction practitioners develop their expertise. Understanding the development of expertise is essential for providers of university education and training to enable them to develop programs to establish on which new professionals can better develop their appropriate expertise. This paper builds on earlier research and further explores how expertise develops in construction professionals. It also explores the similarities and differences in development of that expertise in construction practitioners from the …

Macro, Meso And Micro Perspectives Of Technology Transfer, James A. Cunningham, Paul O'Reilly

Conference Papers

Over the last few decades research into the different aspects of technology transfer has grown significantly that has taken in the main a macro perspective. This research has created a body of knowledge and an evidence base that has contributed original insights in developing the field and also has shaped policymaking and practice. Within the field there is a growing focus on meso and micro aspects of technology transfer and a growing interest in for example role individual actors such as scientists, principal investigators policy makers, TTO actors, supporting institutions and functions such as universities, professional research organizations, technology and …

Self-Healing Asphalt Review: From Idea To Practice, S. Xu, Alvaro García, Junfeng Su, Quantao Liu, Amir Tabakovic, Erik Schlangen

Articles

With the advantages of cost efficiency, noise reduction, and comfort driving experience, asphalt is widely used as a binding material in pavement engineering. However, after years of serving, asphalt concrete gets damaged under cyclic vehicle loading. Meanwhile, due to environmental effects including ageing and moisture damage, asphalt binder becomes brittle with time. As a result, microcracks initiate and grow into larger scales, which accelerates the damaging process and finally leads to distresses like raveling, potholes, cracking, and so on. In 1967, Bazin and Saunier[1] witnessed and reported a temperature related healing phenomenon in asphalt mix after loadings. After that, the …

Maritime Spatial Planning Supported By Infrastructure For Spatial Information In Europe (Inspire), Andrej Abramic, Emanuele Bigagli, Vittorio Barale, Alberto Lorenzo-Alonso, Conor Norton

Articles

The implementation of Directive 2007/2/EC - INSPIRE can improve and actually strengthen the informationmanagement and data infrastructures needed for setting up Maritime Spatial Planning (MSP) processes. Evidencefor this comes from three parallel analyses: links between the MSP Framework Directive and INSPIRE compo-nents and implementation; the availability of marine and maritime data through the INSPIRE Geo-Portal; andthe adequacy of using an INSPIRE data model for mapping maritime spatial plans. Thefirst item identifiesINSPIRE as a relevant instrument not only for data collection, but additionally for increasing transparency of theMSP processes, using already operational national and European data infrastructure. The marine/maritime dataavailability analysis …

Vegetation Mapping Of A Coastal Dune Complex Using Multispectral Imagery Acquired From An Unmanned Aerial System, C. Suo, Eugene Mcgovern, Alan Gilmer

Conference Papers

Vegetation mapping, identifying the distribution of plant species, is important for analysing vegetation dynamics, quantifying spatial patterns of vegetation evolution, analysing the effects of environment changes on vegetation, and predicting spatial patterns of species diversity. Such analysis can contribute to the development of targeted land management actions that maintain biodiversity and ecological functions. This paper represents a methodology for 3D vegetation mapping of a coastal dune complex using a multispectral camera mounted on an Unmanned Aerial System (UAS) with particular reference to the Buckroney dune complex in Co. Wicklow, Ireland. UAS, also known as Unmanned Aerial Vehicles (UAV’s) or drones, …

Capacity Analysis - An Explanatory Framework For Social Innovation In Sustainable Development Initiatives, Gerard Doyle

Conference Papers

The member states of the European Union (EU) are encountering a crisis in terms of resource availability, use and disposal of products (Miller, 2014, and Ellen MacArthur Foundation, 2011). Within the EU, material recycling and waste-based energy recovery secures approximately 5 per cent of the original raw material value (Ellen MacArthur Foundation, 2015). Arising from current high levels of personal consumption and disposal, resources in Ireland are being depleted at an unsustainable rate (Doyle & Davies, 2013). Within the EU, each person consumes, on average,13.3 tonnes(t) of materials annually (EC, 2015a). Much of this is being discarded, with an average …

Thermo-Optic Tuning Of A Packaged Whispering Gallery Mode Resonator Filled With Nematic Liquid Crystal, Vishnu Kavungal, Gerald Farrell, Qiang Wu, Arun Mallik, Yuliya Semenova

Articles

Thermo-optic tuning of whispering gallery modes (WGMs) in a nematic liquid crystal-filled thin-walled capillary tube resonator is reported. WGMs were excited by the evanescent field from a tapered optical fiber. Tapered optical fiber fabrication and reduction of wall thickness of the capillary tube was carried out by a ceramic micro-heater brushing technique. A simple and robust packaging technique is demonstrated to ensure stable and repeatable operation of the device. Tunability of WGMs with temperature was demonstrated with a sensitivity of 267.5 ± 2.5 pm/°C. The demonstrated thermo-optic method for WGMs tuning is potentially useful for many tunable photonic devices and …

Highly Sensitive Twist Sensor Based On Partially Silver Coated Hollow Core Fiber Structure, Dejun Liu, Rahul Kumar, Fangfang Wei, Wei Han, Arun Mallik, Jinhui Yuan, Chongxiu Yu, Feng Li, Zhengyong Liu, Hwa-Yaw Tam, Gerald Farrell, Yuliya Semenova, Qiang Wu

Articles

Interferometer based on multiple beam interferences inside a hollow core fiber (HCF) structure (also known as an antiresonant reflecting optical waveguide) has been attracting interest of many researchers due to its periodic transmission spectrum containing high quality factor spectral dips. Functionalized HCF structures have been demonstrated for a wide range of applications in humidity, magnetic field, and biosensing. Here, we report a new application of the HCF-based structure with a partial silver coating layer for sensing of twist. It is configured by a fusion splicing a section of 4.5-mm long HCF between two standard single mode fibers (SMFs), followed by …

A Pseudo-Microsimulation Approach For Modelling Congested Traffic Loading On Long-Span Bridges, Colm Carey, Colin Caprani, Bernard Enright

Articles

This paper investigates congested traffic loading on long-span bridges through the use of traffic microsimulation. Six months of Weigh-In-Motion free-flow traffic data (including cars) are used as input for the microsimulation of congested traffic. Key parameters that affect traffic loading are identified in the output of the microsimulation, and these parameters form the basis for a more computationally efficient ‘pseudo-microsimulation of congested traffic’ (PMCT) model. This PMCT model is shown to replicate the traffic loading from full microsimulation accurately and allows long-run simulations, equivalent to 1000 years of congested traffic, to be performed with an acceptably short duration. This reduces …

Perspectives On Designing For A Sustainable Future; Products For The Developed And Developing Worlds, Pearl O'Rourke, Colm O'Kane, Keith Colton

Conference Papers

The aim of a sustainable product solution is to fulfil a user need while creating a net positive sustainable impact - environmentally, socially and economically [1]. The concept of sustainability can be complex for a product design student to come to terms with, since the creation of new physical products consumes the Earth’s scarce natural resources [2]. So, should we ideally have no new products in the future? More likely, we should hope to have more sustainably aware product designers, working for companies that need to - due to regulations or consumer preferences - produce and provide more sustainable product …

Design And Manufacture Of A Precast Pcm Enhanced Concrete Cladding Panel For Full Scale Performance Monitoring, Dervilla Niall, Roger West, Oliver Kinnane

Conference papers

The overall aim of this study is to develop innovative precast cladding panels for the renovation of Europe’s existing building stock thereby improving their energy performance. Using the mass of a building to store heat and/or cold can reduce the demand on the auxiliary heating and/or cooling systems and hence reduce the overall energy demand of the building. Previous laboratory research has shown that the incorporation of phase change materials (PCMs) into concrete enhances its thermal storage capacity by up to 50%. However in a real application where a PCM-concrete composite material is used in a building to store thermal …

Calcium Alginate Capsules Encapsulating Rejuvenator As Healing System For Asphalt Mastic, S. Xu, Amir Tabakovic, X. Liu, E. Schlangen

Research and Innovation - Articles

Researchers have demonstrated that the rejuvenator encapsulation method is a promising autonomic self-healing approach for asphalt pavements, where by the self-healing system improves the healing capacity of an asphalt pavement mix. However, potentially high environmental risk via leaching of hazardous chemicals such as melamine formaldehyde renders the technology unsuitable for widespread use in road design. This paper explores the potential for the use of more environmentally friendly and economically viable rejuvenator encapsulation method, where the calcium alginate is used as rejuvenator encapsulation material. The capsule morphology and microstructure were studied using the Microscopy and X-ray tomography. Capsules thermal and mechanical …

Highly Sensitive Displacement Sensor Based On Composite Interference Established Within A Balloon-Shaped Bent Multimode Fiber Structure, Ke Tian, Gerald Farrell, Xianfan Wang, Elfed Lewis, Pengfei Wang

Articles

A novel optical fiber displacement sensor based on composite interference established within a balloon-shaped bent multimode (BSBM) fiber structure is described and experimentally demonstrated. The BSBM fiber structure is realized by bending a straight single-mode–multimode–single-mode (SMS) fiber structure into a balloon shape using a length of capillary tube to fix the shape of the structure. Owing to the bend in the multimode waveguide, the original undistorted multimode interference pattern is changed, and an extra Mach–Zehnder interferometer is effectively introduced within the multimode fiber (MMF) section at a suitable bending radius. This established composite interference greatly improves the displacement sensing performance …

Validating A Reduced-Order Model For Synthetic Jet Actuators Using Cfd And Experimental Data, Tim Persoons, Rick Cressall, Aliimohammadi Sajad

Articles

Synthetic jet actuators (SJA) are emerging in various engineering applications, from flow separation and noise control in aviation to thermal management of electronics. A SJA oscillates a flexible membrane inside a cavity connected to a nozzle producing vortices. A complex interaction between the cavity pressure field and the driving electronics can make it difficult to predict performance. A reduced-order model (ROM) has been developed to predict the performance of SJAs. This paper applies this model to a canonical configuration with applications in flow control and electronics cooling, consisting of a single SJA with a rectangular orifice, emanating perpendicular to the …

Application Of Synthetic Informative Minority Over-Sampling (Simo) Algorithm Leveraging Support Vector Machine (Svm) On Small Datasets With Class Imbalance, Akshatha Fakkeriah Kallappanamatt

Dissertations

Developing predictive models for classification problems considering imbalanced datasets is one of the basic difficulties in data mining and decision-analytics. A classifier’s performance will decline dramatically when applied to an imbalanced dataset. Standard classifiers such as logistic regression, Support Vector Machine (SVM) are appropriate for balanced training sets whereas provides suboptimal classification results when used on unbalanced dataset. Performance metric with prediction accuracy encourages a bias towards the majority class, while the rare instances remain unknown though the model contributes a high overall precision. There are chances where minority instances might be treated as noise and vice versa. (Haixiang et …

Power Loss Comparison Of Dc Side And Ac Side Cascaded Modular Multilevel Inverters, Shahab Sajedi, Malabika Basu, Michael Farrell

Conference papers

High-voltage DC (HVDC) transmission systems

based on voltage source converter technology are increasingly being used for interconnecting power networks and for transporting energy from remote renewable energy sources. Modular multilevel converters (MMCs) are emerging as the technology of choice for future HVDC transmission systems. Several MMC topologies have been introduced for high power applications and among them the AC side and the DC side cascaded topologies have received most interest because of their high efficiency, low switching losses and good modularity. In high power applications, the efficiency of the converter is an important consideration. Hence it is essential converter power …

Assessment Of The Accuracy Of Cable Sheath Fault Location Device And Enhancement Of Its Performance, Niall Kennedy, Joseph Kearney, Tom Looby, Ciaran O'Leary

Conference papers

As power system networks are being constantly upgraded and extended, there is a greater importance in the reliable transmission of electrical power and fault finding techniques, especially for cables installed underground. Damage to a cable’s protective sheath can damage a cables life span and also lead to disruption of system operation and loss of supply. This study includes research into the literature and techniques used to locate these faults accurately. Bridge resistance and volt drop measurement techniques are the main methods used by sheath fault location devices to locate faults accurately. This task is made more difficult because such devices …

Review Of The Effectiveness Of Impulse Testing For The Evaluation Of Cable Insulation Quality And Recommendations For Quality Testing, Adrian Coughlan, Joseph Kearney, Tom Looby

Conference papers

Abstract— This project investigates impulse breakdown testing as a means of determining the as constructed standard of MV power cable. A literature survey is undertaken to elucidate the place of this test in an overall cable test regime and to determine the factors that impact on the performance of the test method. Testing was undertaken on ESB Networks cables to establish if a merit order ranking was feasible based on this test and to determine if the test could detect defects in the inner semiconducting layer. Based on this, conclusions and recommendations are made regarding the overall applicability and usefulness …

Data Driven Prediction Model (Ddpm) For Server Inlet Temperature Prediction In Raised-Floor Data Centers, Raymond Lloyd, Marek Rebow

Conference papers

Data centers account for approx. 1.4% of the world’s electricity consumption, of which up to 50% of that power is dedicated to keeping the actual equipment cool. This represents a huge opportunity to reduce data center energy consumption by tackling the cooling system operations with focus on thermal management. This work presents a novel Data Driven Predictive Model (DDPM) for temperature prediction of server inlet temperatures that utilises high resolution empirical temperature measurements from 52 real-life data centers. A knowledge-base of temperature data and related physical features, created via clustering techniques was used to train a series of artificial neural …

Proportional-Integral And Proportional-Resonant Based Control Strategy For Puc Inverters, Samet Biricik, Hasan Komurcugil

Conference papers

In this paper, a proportional-integral (PI) and proportional-resonant (PR) based control strategy is proposed for packed-U-cell (PUC) inverters. In the conventional PI-PI based control strategy, while the first PI regulates the DC capacitor voltage, the second PI regulates the AC load current. However, it is shown that the second PI cannot guarantee zero tracking error in the load current. The main reason of this comes from the fact that PI controllers are not able to achieve zero tracking error for the AC signals. Also, in an attempt to reduce the tracking error by tuning PI gains distorts the load current. …

A Machine Learning Management Model For Qoe Enhancement In Next-Generation Wireless Ecosystems, Eva Ibarrola, Mark Davis, Camille Voisin, Ciara Close, Leire Cristobo

Conference papers

Next-generation wireless ecosystems are expected to comprise heterogeneous technologies and diverse deployment scenarios. Ensuring a good quality of service (QoS) will be one of the major challenges of next-generation wireless systems on account of a variety of factors that are beyond the control of network and service providers. In this context, ITU-T is working on updating the various Recommendations related to QoS and users' quality of experience (QoE). Considering the ITU-T QoS framework, we propose a methodology to develop a global QoS management model for next-generation wireless ecosystems taking advantage of big data and machine learning. The results from a …

On Fixed Beamforming In Sectored Mmwave Ultra Dense Networks At 73ghz, Jasmina Mcmenamy, Haris Kremo, George A. Ropokis, Adam Narbudowicz

Conference papers

We investigate the use of fixed analogue transmit beamforming for downlink communication in millimetre-wave (mmWave) band ultra-dense networks (UDNs) at 73GHz. Our simulation study is based on 3D radiation patterns using a real design of large planar antenna arrays with different horizontal beamwidths and full characterisation of interference. The effects of network densification are captured through different ratios of the number of access points (APs) to the number of users. We quantify the system's performance by evaluating outage and achievable rate. The results show that users with rates around the mean benefit more from the densification than from narrowing the …

Examining A Hate Speech Corpus For Hate Speech Detection And Popularity Prediction, Filip Klubicka, Raquel Fernandez

Other resources

As research on hate speech becomes more and more relevant every day, most of it is still focused on hate speech detection. By attempting to replicate a hate speech detection experiment performed on an existing Twitter corpus annotated for hate speech, we highlight some issues that arise from doing research in the field of hate speech, which is essentially still in its infancy. We take a critical look at the training corpus in order to understand its biases, while also using it to venture beyond hate speech detection and investigate whether it can be used to shed light on other …

Fatigue And Damage Of Porcine Pars Interarticularis During Asymmetric Loading, Colin Bright, Stephen Tiernan, Fiona Mcevoy, Pat Kiely

Articles

If the articular facets of the vertebra grow in an asymmetric manner, the developed bone geometry causes an asymmetry of loading. When the loading environment is altered by way of increased activity, the likelihood of acquiring a stress fracture may be increased. The combination of geometric asymmetry and increased activity is hypothesised to be the precursor to the stress fracture under investigation in this study, spondylolysis. This vertebral defect is an acquired fracture with 7% prevalence in the paediatric population. This value increases to 21% among athletes who participate in hyperextension sports. Tests were carried out on porcine lumbar vertebrae, …

Surface Water Flooding, Groundwater Contamination, And Enteric Disease In Developed Countries: A Scoping Review Of Connections And Consequences, L. Andrade, J. O'Dwyer, E. O'Neill, Paul Hynds

Articles

Significant volumes of research over the past four decades has sought to elucidate the social, infrastructural, economic, and human health effects of climate change induced surface flooding. To date, epidemiological and public health studies of flooding events have focused on mental health effects, vector-borne diseases, and infectious enteric disease due to floodwater contact (i.e. typically low consumption rates). The inherent nature of groundwater (i.e. out of sight, out of mind) and the widely held belief that aquifers represent a pristine source of drinking water due to natural attenuation may represent the “perfect storm” causing direct consumption of relatively large volumes …

Problem-Based Learning: Student Perceptions Of Its Value In Developing Professional Skills For Engineering Practice, Una Beagon, Dervilla Niall, Eabhnat Ni Fhloinn

Articles

This study explores students’ perceptions of the effectiveness of a Problem-Based Learning (PBL) design project, taken as part of a first-year engineering module, in developing professional skills needed for engineering practice. Students completed surveys before and after the PBL group project, and produced personal reflections on the process. The closed survey questions were analysed quantitatively and the main themes from the reflections outlined using General Inductive Analysis. Students rated themselves as having improved across a range of professional skills as a result of the project, with particular emphasis on teamwork, communication skills, understanding of the design process and self-directed learning. …

High Sensitivity Optical Fiber Sensors For Simultaneous Measurement Of Methanol And Ethanol, Dejun Liu, Rahul Kumarb, Fangfang Wei, Wei Han, Arun Kumar Mallik, Jinhui Yuanc, Shengpeng Wan, Xingdao He, Zhe Kange, Feng Li, Chongxiu Yu, Gerald Farrell, Yuliya Semenova, Qiang Wu

Articles

High sensitivity volatile organic compounds (VOCs) sensors based on a tapered small core single mode fiber (TSCSMF) and a microfiber coupler (MFC) are reported. The TSCSMF had a waist diameter of ~5.1 μm and the MFC had a waist diameter of ~1.9 μm each and both were fabricated using a customized microheater brushing technique. Silica based materials containing immobilized Nile red prepared by sol-gel method with two different recipes (recipe I and recipe II) are investigated. Initially recipe I based coating materials were applied to the surfaces of the TSCSMF and MFC. The experimental results show that the sensor based …

Investigation Of Temperature Dependence Of Microfibre Coil Resonators, Yu Yin, Jibo Yu, Yuxuan Jiang, Shi Li, Jing Ren, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

The temperature-sensitive performance of a microfiber coil resonator (MCR) is thoroughly investigated. The MCR is fabricated by wrapping a microfiber on a PMMA rod coated with a UV-curable low refractive index epoxy. The temperature sensitivity is measured by investigating the correlation between the shift of the resonant wavelength and the surrounding temperature. It is determined that a range of parameters of the MCRs, including the gap between two adjacent rings, the diameter of the supporting rod, the number of rings, and the diameter of the microfiber, have a great influence on the temperature sensitivity of the MCRs. By optimizing the …

Investigation Of A Novel Sms Fiber Based Planar Multimode Waveguide And Its Sensing Performance, Xianfan Wang, Jiquan Zhang, Ke Tian, Shunbin Wang, Libo Yuan, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A novel, MMI-based all-fiber structure, which consists of two single-mode fibers and a multimode fiber polished on both sides, is described. The light propagation characteristics of this fiber structure, as well as its superior sensing performance, are analyzed theoretically by using the beam propagation method (BPM). This fiber structure demonstrates a significant spectral response to changes of the surrounding refractive index (RI), and the measured results exhibit good agreement with the predicted data. The measured average RI sensitivity is as high as 151.29 nm/RIU over an RI range from 1.3450 to 1.4050, when the polished depth is 30 µm on …