Engineering Commons^™

A Simple All-Fiber Comb Filter Based On The Combined Effect Of Multimode Interference And Mach- Zehnder Interferometer, Guorui Zhou, Rahul Kumar, Qiang Wu, W. P. Ng, Richard Binns, Lalam Nageswara, Xinxiang Miao, Longfei Niu, Xiaodong Yuan, Yuliya Semenova, Gerald Farrell, Jinhui Yuan, Chongxiu Yu, Xinzhu Sang, Xiangjun Xin, Bo Liu, Haibing Lv, Yong Qing Fu

Articles

A polarization-dependent all-fiber comb filter based on a combination effect of multimode interference and Mach-Zehnder interferometer was proposed and demonstrated. The comb filter was composed with a short section of multimode fiber (MMF) fusion spliced with a conventional single mode fiber on the one side and a short section of a different type of optical fiber on the other side. The second type of optical fiber is spliced to the MMF with a properly designed misalignment. Different types and lengths of fibers were used to investigate the influence of fiber types and lengths on the performance of the comb filter. …

High-Sensitivity Salinity Sensor Based On Optical Microfiber Coil Resonator, Y. Yin, S. Li, J. Ren, Gerald Farrell, E. Lewis, Pengfei Wang

Articles

In recent years, salinity sensing has attracted much attention in potential areas ranging from marine monitoring, marine circulation, marine climate and environment protection in oceanography [1–4]. Generally, traditional methods of salinity measurement have been based on electronic methods (electrochemical) to detect the existence of chlorine ions of the seawater [5,6]. However, this method is affected greatly from the harsh environment, such as high corrosivity, extreme temperature and strong electromagnetic interference and is not used widely in micro scale due to its large size and complex structure. Electrochemical sensors are also prone to cross-sensitivity from and can even be damaged by …

Silica Gel Coated Spherical Micro Resonator For Ultra-High Sensitivity Detection Of Ammonia Gas Concentration In Air, Arun Mallik, Gerald Farrell, Dejun Liu, Vishnu Kavungal, Qiang Wu, Yuliya Semenova

Articles

A silica gel coated microsphere resonator is proposed and experimentally demonstrated for measurements of ammonia (NH3) concentration in air with ultra-high sensitivity. The optical properties of the porous silica gel layer change when it is exposed to low (parts per million (ppm)) and even ultra-low (parts per billion (ppb)) concentrations of ammonia vapor, leading to a spectral shift of the WGM resonances in the transmission spectrum of the fiber taper. The experimentally demonstrated sensitivity of the proposed sensor to ammonia is estimated as 34.46 pm/ppm in the low ammonia concentrations range from 4 ppm to 30 ppm using an optical …

Evaluating The Effect Of Turbulence On Aircraft During Landing And Take-Off Phases, Anthony O'Connor, Derek Kearney

Articles

— Low level wind shear and turbulence present a serious safety risk to aircraft during the approach, landing and take-off phases. Low level wind shear has been identified as one of the primary factors for aircraft go-arounds and aborted landings. During any given year, wind shear occurs thousands of times at airports around the world, affecting the arrival and departure of aircraft. This paper has quantified the direct cost of flight Go-arounds. This paper will show the potential savings to the aviation industry. This paper will argue that a solution to the problem of forecasting low level wind shear and …

Influence Of Cement Type On The Efficiency Of Electrochemical Chloride Extraction, Brian Norton, Sean Bond, Chahrazed Osmani, Niall Holmes

Conference papers

No abstract provided.

Evaluation Of Wind Energy Forecasts: The Undervalued Importance Of Data Preparation, Gianni Goretti, Aidan Duffy

Conference papers

The evaluation of wind energy forecasts is a key task for those involved in the wind power sector, and the accurate evaluation of forecasts is fundamental to make informed decisions both in business and research. To evaluate the accuracy of a forecast, observed values must be compared against forecast values over a test period. At times, however, the actual generation of a wind farm can be affected by factors that are outside the scope of the forecast model. Evaluating a forecast using a data set that includes such out-of-scope observations might give a biased or inconsistent assessment. In the data …

Quantity Surveying Professional Apprenticeships: A Paragon For The Supply Of Talent In The Irish Construction Industry, Eoghan Ó Murchadha, Roisin Murphy

Conference papers

The construction industry in Ireland has undergone considerable change in the last decade, the effect of which has resulted in a legacy malfunction in the construction labour market. The recent construction downturn led to high levels of construction unemployment, resulting in the mass emigration of construction professionals. Additionally, perceptions of job uncertainty in construction deterred new entrants into construction-related training and education programmes such as Quantity Surveying. If a skills gap is allowed to prevail, then there is a tangible threat to the industry’s cost competitiveness. As such, value for money becomes merely theoretical, and the cost to the economy …

The Impact Of Brexit On Cross-Border Trade By The Construction Sector In Ireland: An Exploratory Study, Tara Brooks, Duga Ewuga, Lloyd Scott, John Spillane

Conference papers

Cross-border co-operation can foster learning and contribute positively to business performance and social cohesion. This paper considers construction firms' economic motivation for co-operation around the Ireland - Northern Ireland border. This area, while impacted by the Brexit uncertainty, shares many of the economic and developmental characteristics of border areas throughout Europe. The purpose of the study is to investigate the impact of Brexit on cross border trade by the construction sector in Ireland and investigate the current tensions and barriers to that sector. A qualitative methodology adopted a literature review and semi-structured interview strategy. Data was collected from purposively selected …

Trades And Apprenticeships Skills Survey: The Employers Perspective, Eoghan Ó Murchadha, Roisin Murphy

Reports

The construction sector in Ireland has gone through a period of extremes in the last decade, from an exceptionally high growth to deep and prolonged recession. The backdrop to this report, however, is one of favourable economic and industry conditions. Economic growth is positive, exchequer balances are improving, unemployment continues to decline and sentiment within the construction industry is strong across most sub-sectors.

The construction labour market however, remains in a state of disequilibrium. The severe recession had devastating consequences on construction firms in Ireland resulting in company closures, redundancy and mass emigration. At the same time the number of …

Solar Alignment And The Irish Passage Tomb Tradition, Frank Prendergast

Book/Book Chapter

A succinct and very useful, illustrated, explanatory guide to the phenomenon of solar alignment in the irish Passage Tomb tradition. Includes a listing of where to visit the 15 known astronomically aligned passage tombs in the 32 counties.

Written by Dr Frank Prendergast who is now Emeritus at the Dublin Institute of Technology, where he researches Irish prehistoric monuments and their landscapes from a cultural astronomy perspective. His current interests and publications are on the meaning of the dark sky in the prehistoric past and on the conservation of archaeological landscapes from light pollution.

Heritage Guides are included free with …

Optical Fiber Fresnel Reflection Sensor For Direct Detection Of The Solid-Liquid Phase Change In N-Octadecane, Wei Han, Marek Rebow, Dejun Liu, Yuliya Semenova, Qiang Wu Prof.

Articles

An all optical fiber Fresnel reflection sensor for detecting the solid–liquid phase change in n-octadecane is proposed and experimentally demonstrated. The sensor probe consists of a single-mode fiber with a cleaved end which is immersed in the material sample under test. As the n-octadecane changes from solid to liquid or from liquid to solid, its refractive index (RI) changes resulting in changes of the light power ratio reflected by the probe. Since the RI of n-octadecane during its phase transition changes discontinuously, inflection in the reflected light power ratio dependence indicates the phase change of the sample in the vicinity …

Preliminary Findings Of A Phenomenological Study Of Middle Eastern Women’S Experiences Studying Engineering In Ireland, Shannon Chance, Bill Williams

Conference papers

This paper reports analysis of phenomenological interviews conducted with eight women studying engineering, all Arabic speakers and practicing Muslims, and all from the countries of Oman and Kuwait. Data were collected as part of a larger study of women’s experiences learning engineering in institutions of higher education in Poland, Portugal, and Ireland. The eight women contributing data for the analysis for this paper were all enrolled on engineering degree programs in Dublin, Ireland, where they studied together. The larger study involves conducting longitudinal data via interviews with 47 women around Europe to understand what their undergraduate experiences in STEM have …

A Model For Spurring Organizational Change Based On Faculty Experiences Working Together To Implement Problem-Based Learning, Shannon Chance, Gavin Duffy

Conference papers

This research paper provides a case study of experiences of engineering faculty members at a large public university in Ireland working together to transform their teaching methods. We investigate eight teachers’ experiences of a faculty-led learning community designed to help individuals transform their courses. This small collection of faculty met regularly to discuss ways to facilitate and assess students working in groups. Outside the group’s meetings, participants brought important issues to the forefront of formal and informal discussion with colleagues. Participation in the learning group encouraged, supported, and helped sustain change. This case study seeks to provide insight and a …

Ambiqual – A Full Reference Objective Quality Metric For Ambisonic Spatial Audio, Miroslaw Narbutt, Andrew Allen, Jan Skoglund, Michael Chinen, Andrew Hines

Conference papers

Streaming spatial audio over networks requires efficient encoding techniques that compress the raw audio content without compromising quality of experience. Streaming service providers such as YouTube need a perceptually relevant objective audio quality metric to monitor users’ perceived quality and spatial localization accuracy. In this paper we introduce a full reference objective spatial audio quality metric, AMBIQUAL, which assesses both Listening Quality and Localization Accuracy. In our solution both metrics are derived directly from the B-format Ambisonic audio. The metric extends and adapts the algorithm used in ViSQOLAudio, a full reference objective metric designed for assessing speech and audio quality. …

Ranking Semantics Based On Subgraphs Analysis, Pierpaolo Dondio

Conference papers

An abstract argumentation framework [15] consists of a direct graph where nodes represent arguments and arrows represent an attack relation among arguments. A semantics is used to evaluate arguments’ acceptability. In the labelling approach [7], this evaluation is done by assigning to each argument a label in, out or undec, meaning that the argument is considered consistently acceptable, non-acceptable or undecided (i.e. no decision can be taken on arguments’ acceptability).

Operation Of Three-Level Single-Phase Half-Bridge Npc Inverter-Based Shunt Active Power Filter Under Non-Ideal Grid Voltage Condition With Sliding Mode Controller, Samet Biricik, Hasan Komurcugil, Tuan Ngo, Malabika Basu

Conference papers

In this paper, a new control method is presented for a single-phase three-level neutral point clamped half-bridge shunt active power filter with the aim of eliminating the grid current harmonics. It is shown that the proposed control me thod accurately detects the positive-sequence voltage component under distorted grid condition. With this feature, the performance of the single-phase active power filter under distorted grid voltage condition is improved considerably. Furthermore, the imbalance in the capacitor voltages which occurs in the half-bridge topology is eliminated by adding a feedback term to the current control loop.

Comparison Of Grid Array And Microstrip Patch Array Antennas At 28 Ghz, Zeeshan Ahmed, Patrick Mcevoy, Max Ammann

Conference papers

A millimeter wave Grid Array Antenna for fifth generation (5G) communications is presented. The 20 cell, nearly-rhombic, 40×40 mm2 Grid Array Antenna structure is simulated and fabricated on a Rogers RT/Duroid 5880 substrate with thickness of 0.25 mm. The grid array has |S11|

Interoperable Ocean Observing Using Archetypes: A Use-Case Based Evaluation, Paul Stacey, Damon Berry

Conference papers

This paper presents a use-case based evaluation of the impact of two-level modeling on the automatic federation of ocean observational data. The goal of the work is to increase the interoperability and data quality of aggregated ocean observations to support convenient discovery and consumption by applications. An assessment of the interoperability of served data flows from publicly available ocean observing spatial data infrastructures was performed. Barriers to consumption of existing standards-compliant ocean-observing data streams were examined, including the impact of adherence to agreed data standards. Historical data flows were mapped to a set of archetypes and a backward integration experiment …

Sliding-Mode And Proportional-Resonant Based Control Strategy For Three-Phase Two-Leg T-Type Grid-Connected Inverters With Lcl Filter, Necmi Altin, Saban Ozdemir, Hasan Komurcugil, Ibrahim Sefa, Samet Biricik

Conference papers

In this study, sliding-mode and proportional-resonant based control strategy is proposed for three-phase two-leg T-type grid-connected inverter with LCL filter. The sliding surface function is formed by using the inverter current and capacitor voltage errors. When the inverter current and capacitor voltage feedbacks are included into the control loop, the active damping requirement is automatically resolved. The PR controllers are employed in cascaded manner to generate the references for inverter current and capacitor voltage. The use of PR controllers ensures zero steady-state error in the inverter current, capacitor voltage and grid current. In addition, since the proposed three-phase inverter has …

Generalized Configurations For The Synchronization System Based On Transfer Function Approach, Tuan Ngo, Tuyen Vu, Samet Biricik

Conference papers

This paper presents our research on deriving all the generalized forms for the grid synchronization system of an inverter in the grid-connected applications. The transfer function approach is introduced in order to obtain the generalized second-order and third-order synchronization systems. This approach is based on the orthogonal property of two outputs from the second-order generalized-integrator (SOGI) technique that these two outputs are always 90° difference in phase but only equal in magnitude at the grid frequency. The proposed approach then can provide the generalized forms of any high-order synchronization system, including the second-order and the third-order systems. It is interesting …

Block-Based Classification Method For Computer Screen Image Compression, Kai Wu, Richard Gahan, Patrick O'Friel

Conference papers

In this paper, a high accuracy and reduced processing time block based classification method for computer screen images is presented. This method classifies blocks into five types: smooth, sparse, fuzzy, text and picture blocks. In a computer screen compression application, the choice of block compression algorithm is made based on these block types. The classification method presented has four novel features. The first novel feature is a combination of Discrete Wavelet Transform (DWT) and colour counting classification methods. Both of these methods have only been used for computer image compression in isolation in previous publications but this paper shows that …

Effect Of High- And Low-Molecular-Weight Hyaluronic-Acid-Functionalized-Az31 Mg And Ti Alloys On Proliferation And Differentiation Of Osteoblast Cells, Sankalp Agarwal, Brendan Duffy, James Curtin, Swarna Jaiswal

Articles

The quality of patient care has increased dramatically in recent years because of the development of lightweight orthopedic metal implants. The success of these orthopedic implants may be compromised by impaired cytocompatibility and osteointegration. Biomimetic surface engineering of metal implants using biomacromolecules including hyaluronic acid (HA) has been used an effective approach to provide conditions favorable for the growth of bone forming cells. To date, there have been limited studies on osteoblasts functions in response to metal substrates modified with the hyaluronic acid of different molecular weight for orthopedic applications. In this study, we evaluated the osteoblasts functions such as …

Impact Of Plasma Jet Geometry On Residence Times Of Radical Species, James Lalor, Laurence Scally, Patrick J. Cullen, Vladimir Milosavljevic

Articles

Numerous electrode geometries and power supplies, both commercial and in-house, have been employed for the generation of low-temperature atmospheric plasma jets. In this work, the development and operation of a 12 jet nonthermal atmospheric plasma system is presented. The study is based on optical spectroscopy as a diagnostic method due to its nonintrusive nature. A key focus of this study was the material selection (conductive and nonconductive), with several polymers screened for the jet design leading to polyacetal as the choice material. Their results are compared with other atmospheric plasma jet systems. The results show a significant increase in residence …

“Woodlands” - A Virtual Reality Serious Game Supporting Learning Of Practical Road Safety Skills., Krzysztof Szczurowski, Matt Smith

Conference Papers

In developed societies road safety skills are taught early and often practiced under the supervision of a parent, providing children with a combination of theoretical and practical knowledge. At some point children will attempt to cross a road unsupervised, at that point in time their safety depends on the effectiveness of their road safety education. To date, various attempts to supplement road safety education with technology were made. Most common approach focus on addressing declarative knowledge, by delivering road safety theory in an engaging fashion. Apart from expanding on text based resources to include instructional videos and animations, some stakeholders …

Protocol For Energy Efficient Cluster Head Election For Collaborative Cluster Head Elections., David Otu

Dissertations

In wireless sensor networks (WSNs) , energy is a major constrain.Energy efficient network protocols is required to maintain reliable sensing of the sensing field . WSNs that use LEACH protocol, have node in a cluster periodically take trials to become cluster - head,such that the nodes in the cluster becomes cluster - head evenly. Nodes with greater transmission distance to the base station in the cluster dies out faster because it performs more work in transmitting data when it is cluster-head. The distance-based algorithm presented in this project, ensures that work is allocated to the nodes in the cluster more …

An Application Of Natural Language Processing For Triangulation Of Cognitive Load Assessments In Third Level Education, Luis Alfredo Contreras

Dissertations

Work has been done to measure Mental Workload based on applications mainly related to ergonomics, human factors, and Machine Learning. The influence of Machine Learning is a reflection of an increased use of new technologies applied to areas conventionally dominated by theoretical approaches. However, collaboration between MWL and Natural Language Processing techniques seems to happen rarely. In this sense, the objective of this research is to make use of Natural Languages Processing techniques to contribute to the analysis of the relationship between Mental Workload subjective measures and Relative Frequency Ratios of keywords gathered during pre-tasks and post-tasks of MWL activities …

Can Threshold-Based Sensor Alerts Be Analysed To Detect Faults In A District Heating Network?, Liam Cantwell

Dissertations

Older IoT “smart sensors” create system alerts from threshold rules on reading values. These simple thresholds are not very flexible to changes in the network. Due to the large number of false positives generated, these alerts are often ignored by network operators. Current state-of-the-art analytical models typically create alerts using raw sensor readings as the primary input. However, as greater numbers of sensors are being deployed, the growth in the number of readings that must be processed becomes problematic. The number of analytic models deployed to each of these systems is also increasing as analysis is broadened. This study aims …

Elasticity Measurement In Caas Environments - Extending The Existing Bungee Elasticity Benchmark To Aws's Elastic Container Service, Nora Limbourg

Dissertations

Rapid elasticity and automatic scaling are core concepts of most current cloud computing systems. Elasticity describes how well and how fast cloud systems adapt to increases and decreases in workload. In parallel, software architectures are moving towards employing containerised microservices running on systems managed by container orchestration platforms. Cloud users who employ such container-based systems may want to compare the elasticity of different systems or system settings to ensure rapid elasticity and maintain service level objectives while avoiding over-provisioning. Previous research has established a variety of metrics to measure elasticity. Some existing benchmark tools are designed to measure elasticity in …

Use Of Hyperspectral Images (Hsi) And Convolutional Neural Network (Cnn) To Identify Normal, Precancerous And Cancerous Tissues, Pallavi Jain

Dissertations

Cancer detection has been a great topic of research for a long time, as early detection of cancer can help in increasing the survival rate of patients by providing on time better treatment. A robust system is required in order to detect early-stage cancer as its difficult to identify early-stage cancer from the normal clinical process. The computer vision techniques provide a new way to understand the challenges related to the medical image analysis. This thesis presents the medical image analysis using a combination of Convolutional Neural Network and Hyperspectral Images of cancer patient's tissues. The idea behind choosing the …

From Business Understanding To Deployment: An Application Of Machine Learning Algorithms To Forecast Customer Visits Per Hour To A Fast-Casual Restaurant In Dublin, Odunayo David Adedeji

Dissertations

This research project identifies the significant factors that affects the number of customer visits to a fast-casual restaurant every hour and proceeds to develop several machine learning models to forecast customer visits. The core value proposition of fast-casual restaurants is quality food delivered at speed which means they have to prepare meals in advance of customers visit but the problem with this approach is in forecasting future demand, under estimating demand could lead to inadequate meal preparation which would leave customers unsatisfied while over estimation of demand could lead to wastage especially with restaurants having to comply with food safety …