Engineering Commons^™

Reformulating The Binary Masking Approach Of Adress As Soft Masking, Ruairí De Fréin

Articles

Binary masking forms the basis for a number of source separation approaches that havebeen successfully applied to the problem of de-mixing music sources from a stereo recording.A well-known problem with binary masking is that, when music sources overlap in the time-frequencydomain, only one of the overlapping sources can be assigned the energy in a particulartime-frequency bin. To overcome this problem, we reformulate the classical pan-pot source separationproblem for music sources as a non-negative quadratic program. This reformulation gives rise toan algorithm, called Redress, which extends the popular Adress algorithm. It works by definingan azimuth trajectory for each source based on …

A Wide Frequency Scanning Printed Bruce Array Antenna With Bowtie And Semi-Circular Elements, Zeeshan Ahmed, Patrick Mcevoy, Max Ammann

Articles

A printed edge-fed counterpart of the wire Bruce array antenna, for frequency scanning applications, is presented in this paper. The unit-cell of the proposed antenna consists of bowtie and semi-circular elements to achieve wide bandwidth from below 22 GHz to above 38 GHz with open-stopband suppression. The open-stopband suppression enables a wide seamless scanning range from backward, through broadside, to forward endfire. A sidelobe threshold level of −10 dB is maintained to evaluate efficient scanning performance of the antenna. The antenna peak realized gain is 15.30 dBi, and, due to its compact size, has the ability to scan from −64° …

Spectral Dependence Of Transmission Losses In High-Index Polymer Coated No-Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova

Articles

A high-index polymer coated no-core fiber (PC-NCF) is effectively a depressed core fiber, where the light is guided by the anti-resonant, inhibited coupling and total internal reflection effects and the dispersion diagram shows periodic resonant and anti-resonant bands. In this paper, the transmission spectra of the straight and bent PC-NCFs (length > 5 cm) are measured and analyzed from a modal dispersion perspective. For the purpose of the study, the PC-NCFs are contained within a fiber hetero-structure using two single-mode fiber (SMF) pigtails forming a SMF-PC-NCF-SMF structure. The anti-resonance spectral characteristics are suppressed by the multimode interference in the PC-NCF with …

The Effect Of High Background And Dead Time Of An Ingaas/Inp Single-Photon Avalanche Photodiode On The Registration Of Microsecond Range Near-Infrared Luminescence, P. S. Parfenov, A. P. Litvin, D. A. Onishchuk, K. A. Gonchar, Kevin Berwick, A. V. Fedorov, A. V. Baranov

Articles

The effects of a high background count and a microsecond dead time interval on a gated InGaAs/InP single-photon avalanche photodiode (SPAD) during microsecond luminescence decay registration are discussed. It is shown that the background count rate of the SPAD limits its use for time-resolved and steady-spectral measurements, and that a “pile-up” effect appears in the microsecond range.

Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov

Articles

Perovskites are solution-processed, high-performance semiconductors of interest in low-cost photovoltaics. The interfaces between the perovskite photoactive layers and the top and bottom contacts are crucial for efficient charge transport and minimizing trapping. Control of the collection of charge carriers at these interfaces is decisive to device performance. Here, we review recent progress in the realization of efficient perovskite solar cells using cheap, easily processed, stable, carbon-based interlayers. Interface materials including graphene, carbon nanotubes, fullerenes, graphene quantum dots and carbon dots are introduced and their influence on device performance is discussed.

The Missing Parameter In Renewable Energy Power Quality Analysis, I.E. The Coefficient Of Variation: Case Study Of A 3-Mw On-Site Wind Turbine Project In Ireland, Tony Kealy

Articles

Businesses are employing distributed generation techniques, such as wind turbines, to decarbonise their electrical energy supply by reducing their dependence on fossil-fuel-generated energy. This study investigates the effectiveness of a company making a €3,500,000 investment in a 3-MW on-site wind turbine to supply some or all of their factory electrical loads. The results should benefit the investing company and other potential investors by evaluating the economic, environmental, and social outcomes of the investment. A case study methodology was used. The study found that the payback period was six and a half years, and the turbine installation benefited the environment by …

Energy Performance Certification: Misassessment Due To Assuming Default Heat Losses, Ciara Ahern, Brian Norton

Articles

Energy Performance Certificates (EPCs) are issued when dwellings are constructed, sold or leased in the EU. Where the cost of obtaining the required data is prohibitive, EPC assessors use nationally applicable default-values. To ensure that dwellings are not assigned a wrongly-higher EPC rating, a standardised thermal bridging transmittance coefficient (Y-value) is typically adopted for all existing dwellings while worst-case overall heat loss coefficients (U-values) are used. Default U-values are applied to a specific building element type (roof, wall, floor etc.) based on building codes and regulations applicable at time of construction. Due to significant building fabric upgrades, default U-values are …

A-Step 2030 – New Research Project Presents A Picture Of The Skills Needed For Engineers To Solve The Sustainable Development Goals (Sdgs)., Una Beagon

Articles

Communication and Technical Skills will still be the most important attributes required of engineers in the future, according to a new study by the A-STEP 2030 Erasmus+ funded project. The project which is led by ENSTA Bretagne, France and has academic partners in TU Dublin, Metropolia University of Applied Sciences in Finland and Aalborg University in Denmark aims to develop innovative teaching approaches for engineering students which will attract a more diverse student body to the engineering profession.

Contextual Influences On Human Resources Development: Considerations And Evaluations On The Various External And Internal Factors That Shape And Influence Hrd In Organisations, Charles Alves De Castro

Articles

This article aims to briefly understand and evaluate the main external and internal factors that impact directly on human resources development area within the organisations, mainly related to multinational companies. Also, it discusses the various aspects and influences on HRD-(Human Resources Development) such as societal, organisational/local, global, that impacts on costs, environment, regulations, policies, culture, beliefs, technology and values. This research was carried out by way of a literature review. This is important to demonstrate, explain and evaluate the current existent literature about this specific theme covered in this article. Furthermore, through this review we compared previous research on HRD. …

Experimental Investigation Of Flow Pulsation Waveforms In Rectangular Mesochannels For High Heat Flux Electronics Cooling, Jaakko Mcevoy, Sajad Alimohammadi, Tim Persoons

Articles

The ever rising heat fluxes encountered in electronic devices present a challenging thermal engineering problem. Not only is heat transfer enhancement a goal but more recently control of the enhancement is desired, especially in large scale data facilities where the heated outlet coolant fluid may be of use. Flow pulsation is one of the most common active heat transfer enhancement methods studied across all heat sink sizes. While the effects of pulsation have been shown to increase heat transfer under certain conditions there is still disagreement upon its merit for practical applications, with the majority of previous research has been …

A Generalisable Bottom-Up Methodology For Deriving A Residential Stock Model From Large Empirical Databases, Ciara Ahern, Brian Norton

Articles

Specifying representative reference buildings as a prerequisite for calculating cost-optimal energy performance requirements for buildings and building elements. Appropriate characterisation is prerequisite data for an overall national building energy consumption model to produce valid outcomes. Energy Performance Certificates (EPCs) are issued in the EU, for dwellings whenever they are constructed, sold or leased. Where acquiring data for an EPC would be prohibitively costly, nationally applicable default-values are employed for the building envelope thermal transmittance coefficients. Significant levels of retrofits led to the default-values used now being higher than is typical in reality, leading to characterisations of reference dwellings based on …

Thermal Energy Refurbishment Status Of The Irish Housing Stock, Ciara Ahern, Brian Norton

Articles

Energy Performance Certificates (EPCs) are issued for buildings constructed, sold or leased across the EU. Using a generalizable methodology this work exploits Ireland's EPC national dwelling stock database to determine the thermal refurbishment status of Ireland's housing stock. It is estimated in 2014 that; i) 58% of walls were insulated at a mean overall heat loss coefficient or U-value of 0.66 W/m²K, ii) 67% of roofs were insulated at a mean U-value 0.37 W/m²K, iii) 97% of windows were double-glazed, and iv) 53% of floors were insulated to a mean U-value of 0.59 W/m²K. …

Size Matters: The Impact Of Training Size In Taxonomically-Enriched Word Embeddings, Alfredo Maldonado, Filip Klubicka, John D. Kelleher

Articles

Word embeddings trained on natural corpora (e.g., newspaper collections, Wikipedia or the Web) excel in capturing thematic similarity (“topical relatedness”) on word pairs such as ‘coffee’ and ‘cup’ or ’bus’ and ‘road’. However, they are less successful on pairs showing taxonomic similarity, like ‘cup’ and ‘mug’ (near synonyms) or ‘bus’ and ‘train’ (types of public transport). Moreover, purely taxonomy-based embeddings (e.g. those trained on a random-walk of WordNet’s structure) outperform natural-corpus embeddings in taxonomic similarity but underperform them in thematic similarity. Previous work suggests that performance gains in both types of similarity can be achieved by enriching natural-corpus embeddings with …

Thermal Refurbishment Status Of The Irish Housing Stock, Ciara Ahern, Brian Norton

Articles

Energy Performance Certificates (EPCs) are issued for buildings constructed, sold or leased across the EU. Using a generalizable methodology this work exploits Ireland’s EPC national dwelling stock database to determine the thermal refurbishment status of Ireland’s housing stock. It is estimated in 2014 that; i) 58% of walls were insulated at a mean overall heat loss coefficient or U-value of 0.66 W/m 2 K, ii) 67% of roofs were insulated at a mean U-value 0.37 W/m 2 K, iii) 97% of windows were double-glazed, and iv) 53% of floors were insulated to a mean U-value of 0.59 W/m 2 K. …

Accelerated Capital Allowances: An Overview, Bernard Doherty, James Mc Mahon, William Coffey, Ger Nagle, Kevin Delaney

Articles

ACA is based on the existing capital allowances tax structure or wear and tear allowance, for plants and machinery. Claiming the ACA is carried out the same way as for the standard capital allowances.

Organisations who invest in eligible energy-efficient capital equipment can deduct the full cost of the equipment from their profits in the year of purchase. This reduces the taxable profit in year one by the full cost of the equipment.

A Techno-Economic Analysis Of Current Cooling Techniques In Irish Data Centres, Lee Gibbons, Bryan Coyne, David Kennedy, Sajad Alimohammadi

Articles

This research is part of a comprehensive study to determine reformative actions for cooling regimes within the Irish data centre market. To achieve this goal, preliminary Exergy, Entropy change and operational cost analyses are used. It is determined that there is no clear advantage for using one cooling method over another without knowing the data centres secondary function (e.g. district heating, energy generation). Air cooling technology is a good candidate for a highly reliable system due to the low exhaust temperatures of 30°C. Two-phase immersion is a possibility for economically viable data centres where operational costs are to be minimised, …

Optimizing The Valorization Of Industrial By-Products For The Induction Healing Of Asphalt Mixtures, Amir Tabakovic, Marta Vila-Cortavitarte, Daniel Jato-Espino, Daniel Castro-Fresno

Articles

Self-healing within asphalt pavements is the process whereby road cracks can be repaired automatically when thermal and mechanical conditions are met. To accelerate and improve this healing process, metal particles are added to asphalt mixtures. However, thisapproach is costly both in economic and environmental terms due to the use of virgin metallic particles. So, even though the self-healing of asphalt mixtures has been widely addressed in experimental terms over the years, there is a lack of research aimed at modelling this phenomenon, especially with the purpose of optimizing the use of metal particles through the valorization of industrial by-products. As …

Multi-Objective Layout Optimization Of A Generic Hybrid-Cooled Data Centre Blade Server, Assel Sakanova, Sajad Alimohammadi, Jaakko Mcevody, Sara Battaglioli, Tim Persoons

Articles

The rapid global increase in energy consumption by data centres requires new improved cooling solutions and techniques to be developed and implemented. In a typical data centre, approximately a third of the total power consumption is needed for the cooling infrastructure, resulting in high power usage effectiveness (PUE) values. The main culprits of raised PUE are legacy air-cooled data centres, exhausting only low grade waste heat for which capture and re-use is challenging. This study investigates numerically the potential for energy recuperation by a server-level internal layout optimization for a hybrid air/liquid-cooled server. The approach combines multi-objective genetic algorithm (MOGA) …

Ka-Band Planar Vivaldi Antenna With A Core For High-Gain, Manh Ha Hoang, Kansheng Yang, Matthias John, Patrick Mcevoy, Max Ammann

Articles

A planar Vivaldi antenna structure with a core element is proposed for high gain. Techniques to achieve a significant gain improvement over the full Ka (24-40 GHz) band are implemented; including a frequency-independent excitation method, the introduction of logarithmic ripple on the lateral edges and enclosing the antenna in a dielectric material.

Temperature-Compensated Magnetic Field Sensing With A Dual-Ring Structure Consisting Of Microfiber Coupler-Sagnac Loop And Fiber Bragg Grating - Assisted Resonant Cavity, Fangfang Wei, Dejun Liu, Arun Kumar Mallik, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

A novel temperature-compensated magnetic field sensor based on a ring erbium-doped fiber laser combined with a fiber Bragg grating (FBG) and a Sagnac loop containing a microfiber coupler (MFC) and magnetic fluid is proposed and investigated. Thanks to the dual-ring structure of the MFC-Sagnac loop and the FBG-assisted resonant cavity, the output of the structure has two distinct laser peaks. In addition to the magnetic field sensing capability, the proposed structure can simultaneously provide temperature information. The maximum experimentally demonstrated sensitivity to a magnetic field determined from the spectral shift of one laser peak is 102 pm/mT in the magnetic …

The Influence Of Asphalt Ageing On Induction Healing Effect On Porous Asphalt Concrete, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Induction healing is a proven technology which is able to improve the self‐healing capacity of asphalt concrete. Healing is achieved via electromagnetic current produced by passing induction machine, where steel asphalt constituents heat up which in turn soften the bitumen in the asphalt layer, allowing it to flow and close cracks, repairing the damage. This paper reports on the study which investigated the influence of ageing on the healing capacity of Porous Asphalt (PA) concrete. Porous Asphalt concrete mix was prepared first, then subjected to an accelerated (laboratory) ageing process using a ventilated oven. In order to further evaluate the …

Discussion: Effect Of Bentonite Slurry Pressure On Interface Friction Of Pipe Jacking, Ciaran Reilly, Trevor Orr

Articles

Pipe jacking is a technique used to construct tunnels by pushing prefabricated pipes through the ground from an entrance shaft to an exit shaft. This technique is referred as microtunneling in U.S. terminology, therefore, in the rest of the text, pipejacking and microtunneling will be used as having the same meaning. Pipe jacking is a more economical alternative to segmental lined tunnels. However, the main limitation of pipe jacking is the jacking distance, which is directly dependent on the friction between the pipe and the soil. Therefore, reducing the friction between the pipe and soil is a critical issue in …

Level Of Service And The Transit Neighbourhood: Observations From Dublin City And Surburbs, David O'Connor, Brian Caulfield

Articles

Few studies have looked at the impact Level-of-Service (LOS) might have on the distances people walk to public transport. The relationship, if any, has implications for transit-oriented-development and the viability of different transit modes serving suburban areas. This paper examines pedestrian catchment areas and LOS across a light rail, a metro rail and two bus corridors in Dublin. Public transport users have been surveyed at 17 stops around the city and their trip origin identified. Catchment areas for bus services with high levels of service were found to be comparable and often greater than those for LRT or metro …

A Deep Recurrent Q Network Towards Self-Adapting Distributed Microservices Architecture (In Press), Basel Magableh

Articles

One desired aspect of microservices architecture is the ability to self-adapt its own architecture and behaviour in response to changes in the operational environment. To achieve the desired high levels of self-adaptability, this research implements the distributed microservices architectures model, as informed by the MAPE-K model. The proposed architecture employs a multi adaptation agents supported by a centralised controller, that can observe the environment and execute a suitable adaptation action. The adaptation planning is managed by a deep recurrent Q-network (DRQN). It is argued that such integration between DRQN and MDP agents in a MAPE-K model offers distributed microservice architecture …

A Framework For Evaluating Model-Driven Self-Adaptive Software Systems, Basel Magableh

Articles

In the last few years, Model Driven Development (MDD), Component-based Software Development (CBSD), and context-oriented software have become interesting alternatives for the design and construction of self-adaptive software systems. In general, the ultimate goal of these technologies is to be able to reduce development costs and effort, while improving the modularity, flexibility, adaptability, and reliability of software systems. An analysis of these technologies shows them all to include the principle of the separation of concerns, and their further integration is a key factor to obtaining high-quality and self-adaptable software systems. Each technology identifies different concerns and deals with them separately …

Context Oriented Software Middleware, Basel Magableh

Articles

This article proposes a new paradigm for building an adaptive middleware that supports software systems with self-adaptability and dependability. In this article, we wish to explore how far we can support the engineering of self- adaptive applications using a generic and platform-independent middleware architecture provided by non-specialised programming languages such as Context-Oriented Programming (COP), and Aspect-Oriented Programming (AOP), and not limited to a specific platform or framework. This gives the software developers the flexibility to construct a self-adaptive application using a generic and reusable middleware components that employ popular design patterns, instead of forcing the software developers to use a …

Deep Q Learning For Self Adaptive Distributed Microservices Architecture (In Press), Basel Magableh

Articles

One desired aspect of a self-adapting microservices architecture is the ability to continuously monitor the operational environment, detect and observe anomalous behavior, and provide a reasonable policy for self-scaling, self-healing, and self-tuning the computational resources in order to dynamically respond to a sudden change in its operational environment. The behaviour of a microservices architecture is continuously changing overtime, which makes it a challenging task to use a statistical model to identify both the normal and abnormal behaviour of the services running. The performance of the microservices cluster could fluctuate around the demand to accommodate scalability, orchestration and load balancing demands. …

The Effect Of Impact Location On Brain Strain, Stephen Tiernan, Gary Byrne Mr

Articles

Objective: To determine the effect of impact direction on strains within the brain.

Research design: Laboratory drop tests of hybrid III head-form and finite element simulation of impacts.

Methods and procedures: A head-form instrumented with accelerometers and gyroscopes was dropped from 10 different heights in four orientations: front, rear, left and right hand side. Twelve impacts with constant impact energy were chosen to simulate, to determine the effect of impact location. A finite element head model was used to simulate these impacts, using 6 degrees of freedom. Following this a further set of simulations were performed, where the same acceleration …

A New Era For Reuse Social Enterprises In Ireland? The Capacities Required For Achieving Sustainability, Gerard Doyle

Articles

The conventional linear relationship between production and consumption is no longer sustainable. A key component of the transition towards a more sustainable society is the continuation in use of products for longer and the development of a repair and reuse culture. Reuse social enterprises contribute to addressing a range of environmental, economic and social issues facing urban areas. This paper is concerned with, firstly, the motivations for citizens to establish reuse social enterprises in Ireland. Secondly, the paper examines the factors that contribute to reuse social enterprises in Ireland becoming sustainable.

The research points to the necessity of reuse social …

Distribution Of Tm 3+ And Ni 2+ In Chalcogenide Glass Ceramics Containing Ga2s3 Nanocrystals: Influence On Photoluminescence Properties, Xiaosong Lu, Zhiqiang Lai, Jing Ren, Lukas Strizik, Tomas Wagner, Yanqiu Du, Gerald Farrell, Pengfei Wang

Articles

The distribution of Tm3+ and Ni2+ ions is unambiguously exhibited in 80GeS2-20Ga2S3 chalcogenide glass ceramics (GCs) containing Ga2S3 nanocrystals (NCs) by using advanced analytical transmission electron microscopy. Distinctively different distribution patterns of Tm3+ and Ni2+ ions are observed in the GCs obtained by controlled crystallization. The distribution of the dopants imposes strong influence on their optical properties which are revealed by absorption and photoluminescence (PL) spectra. Detailed discussions are given of the mechanisms of the crystallization-induced PL enhancement and quenching of the Tm3+ mid-infrared and Ni2+ near-infrared emissions, respectively.