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Articles 2671 - 2700 of 4606

Full-Text Articles in Engineering

Robustness Of Speech Quality Metrics To Background Noise And Network Degradations: Comparing Visqol, Pesq And Polqa, Andrew Hines, Naomi Harte, Jan Skoglund, Anil Kokaram Jan 2013

Robustness Of Speech Quality Metrics To Background Noise And Network Degradations: Comparing Visqol, Pesq And Polqa, Andrew Hines, Naomi Harte, Jan Skoglund, Anil Kokaram

Conference papers

The Virtual Speech Quality Objective Listener (ViSQOL) is a new objective speech quality model. It is a signal based full reference metric that uses a spectro-temporal measure of similarity between a reference and a test speech signal. ViSQOL aims to predict the overall quality of experience for the end listener whether the cause of speech quality degradation is due to ambient noise, or transmission channel degradations. This paper describes the algorithm and tests the model using two speech corpora: NOIZEUS and E4. The NOIZEUS corpus contains speech under a variety of background noise types, speech enhancement methods, and SNR levels. …


Monitoring The Effects Of Temporal Clipping On Voip Speech Quality, Andrew Hines, Naomi Harte, Jan Skoglund, Anil Kokaram Jan 2013

Monitoring The Effects Of Temporal Clipping On Voip Speech Quality, Andrew Hines, Naomi Harte, Jan Skoglund, Anil Kokaram

Conference papers

This paper presents work on a real-time temporal clipping monitoring tool for VoIP. Temporal clipping can occur as a result of voice activity detection (VAD) or echo cancellation where comfort noise in used in place of clipped speech segments. The algorithm presented will form part of a no-reference objective model for quantifying perceived speech quality in VoIP. The overall approach uses a modular design that will help pinpoint the reason for degradations in addition to quantifying their impact on speech quality. The new algorithm was tested for VAD compared over a range of thresholds and varied speech frame sizes. The …


Power Quality Improvement Of Distributed Generation Integrated Network With Unified Power Quality Conditioner., Shafiuzzaman Khan Khadem Jan 2013

Power Quality Improvement Of Distributed Generation Integrated Network With Unified Power Quality Conditioner., Shafiuzzaman Khan Khadem

Doctoral

With the increased penetration of small scale renewable energy sources in the electrical distribution network, maintenance or improvement of power quality has become more critical than ever where the level of voltage and current harmonics or disturbances can vary widely. For this reason, Custom Power Devices (CPDs) such as the Unified Power Quality Conditioner (UPQC) can be the most appropriate solution for enhancing the dynamic performance of the distribution network, where accurate prior knowledge may not be available. Therefore, the main objective of the present research is to investigate the (i) placement (ii) integration (iii) capacity enhancement and (iv) real …


Futures Methodology As An Analysis And Planning Tool Within The Commercial Real Estate Industry, An Interpretative Study, Dominika Brodowicz Jan 2013

Futures Methodology As An Analysis And Planning Tool Within The Commercial Real Estate Industry, An Interpretative Study, Dominika Brodowicz

Doctoral

Currently, the majority of methods used in the commercial real estate analysis and planning processes have retrospective and quantitative roots and are based on historic data and trend extrapolation. This approach is based on the assumption that the relationships among key commercial property market variables and trends are constant and develop in a predictable manner into the future. Meanwhile, contemporary real estate companies, which are the subject of this study, are faced with rapid change, often of a discontinuous nature, in their external and internal environments. Furthermore, some of the challenges facing this industry, like social sustainability and a shift …


Rf Breast Cancer Detection Employing A Non-Characterized Vivaldi Antenna And A Music-Inspired Algorithm, Giuseppe Ruvio, Raffaele Solimene, Antonietta D'Alterio, Max Ammann, Rocco Pierri Jan 2013

Rf Breast Cancer Detection Employing A Non-Characterized Vivaldi Antenna And A Music-Inspired Algorithm, Giuseppe Ruvio, Raffaele Solimene, Antonietta D'Alterio, Max Ammann, Rocco Pierri

Articles

A novel microwave breast cancer detection system consisting of an Evolutionary Global Optimized Vivaldi antenna and an algorithm inspired by MUltiple SIgnal Classification (MUSIC) is presented. Its performance is assessed by using a simplified numerical breast phantom for a number of critical conditions including the presence of fibroglandular tissues.


Reversible Photoluminescence Quenchin Of Cdse/Zns Quantum Dots Embedded In Porous Glass By Ammonia Vapor, A. O. Orlova, Yu A. Gromova, V. G. Maslov, O. V. Andreeva, A. V. Baranov, A. V. Federov, A. V. Prudnikau, M. V. Artemyev, Kevin Berwick Jan 2013

Reversible Photoluminescence Quenchin Of Cdse/Zns Quantum Dots Embedded In Porous Glass By Ammonia Vapor, A. O. Orlova, Yu A. Gromova, V. G. Maslov, O. V. Andreeva, A. V. Baranov, A. V. Federov, A. V. Prudnikau, M. V. Artemyev, Kevin Berwick

Articles

The photoluminescence response of semiconductor CdSe/ZnS quantum dots embedded in a borosilicate porous glass matrix to exposure to ammonia vapor is investigated. Formation of surface complexes on the quantum dots results in quenching of the photoluminescence and a shortening of the luminescence decay time. The process is reversible, desorption of ammonia molecules from the quantum dot surface causes the photoluminescence to recover. The sensitivity of the quantum dot luminescence intensity and decay time to the interaction time and the reversibility of the photoluminescence changes makes the CdSe/ZnS quantum dot in porous glass system a candidate for use as an optical …


Ultrasound For Improved Crystallisation In Food Processing, N. Misra, Navneet Deora, Brijesh Tiwari, Patrick J. Cullen Jan 2013

Ultrasound For Improved Crystallisation In Food Processing, N. Misra, Navneet Deora, Brijesh Tiwari, Patrick J. Cullen

Articles

Within the food industry, controlling crystallisation is a key factor governing food structure, texture and consumer appeal, with some foods requiring the promotion of crystallisation in a controlled manner (e.g. chocolate) and others a check (e.g. in honey). Sonocrystallisation is the application of ultrasound energy to control the nucleation of a crystallisation process. The use of power ultrasound provides a non-invasive approach to producing crystals with desired properties. Sonocrystallisation facilitates process control, primarily by modulating crystal size distribution and morphology. This paper details the governing mechanisms of sonocrystallisation. Proven and potential applications of the process in foods, including chocolates, honey, …


Predicting Stock Market Using Online Communities Raw Web Traffic Streams, Pierpaolo Dondio Dec 2012

Predicting Stock Market Using Online Communities Raw Web Traffic Streams, Pierpaolo Dondio

Articles

This paper investigates the predictive power of online communities traffic in regard to stock prices. Using the largest dataset to date, spanning 8 years and almost the complete set of SP500 stocks, we analyze the predictive power of raw unstructured traffic by filtering stock daily returns with traffic features. Our results partially challenge the assumption that raw traffic simply trails stock prices, as expected from a noisy signal without the sentiment direction. Raw traffic is shown to predict prices with statistical significance but with small economic impact. Anyway, this impact rises to moderate under the following conditions: 3 to 7 …


Reducing In-Stent Restenosis Through Novel Stent Flow Field Augmentation, Eoin Murphy, Fergal Boyle Dec 2012

Reducing In-Stent Restenosis Through Novel Stent Flow Field Augmentation, Eoin Murphy, Fergal Boyle

Articles

In-stent restenosis (ISR), manifested as a re-narrowing of the arterial lumen post-implantation of a stent, is a detrimental limitation of stent technology. Understanding and consequently devising ways of reducing the frequency of ISR has been a continuing goal of research into improved stent designs. The biological processes that can lead to ISR have been found to be partially flow dependent with the local hemodynamics at the arterial wall of crucial importance. This paper investigates these biological processes and their instigating factors. Furthermore, the history and theory behind three stent technologies which endeavour to reduce ISR rates through stent flow field …


Prediction Of Compressive Creep Bhaviour In Flexible Polyurethane Foam Over Long Time Scales And At Elevated Temperatures, Conor Briody, Barry Duignan, Stephen Jerrams, Stephen Ronan Dec 2012

Prediction Of Compressive Creep Bhaviour In Flexible Polyurethane Foam Over Long Time Scales And At Elevated Temperatures, Conor Briody, Barry Duignan, Stephen Jerrams, Stephen Ronan

Articles

Compressive creep gradually affects the structural performance of flexible polymeric foam material over extended time periods. When designing components, it is often difficult to account for long-term creep, as accurate creep data over long time periods or at high temperatures is often unavailable. This is mainly due to the lengthy testing times and/or inadequate high temperature testing facilities. This issue can be resolved by conducting a range of short-term creep tests and applying accurate prediction methods to the results. Short-term creep testing was conducted on viscoelastic polyurethane foam, a material commonly used in seating and bedding systems. Tests were conducted …


A Simulation-Based Decision Support System To Model Complex Demand Driven Heathcare Facilities, Amr Arisha, Michael Thorwarth Dec 2012

A Simulation-Based Decision Support System To Model Complex Demand Driven Heathcare Facilities, Amr Arisha, Michael Thorwarth

Conference papers

Simulating healthcare processes is a sophisticated endeavor. Treatment processes and patient arrival patterns differ significantly in their statistical attributes and implicate a high degree of variability. In addition, there are several types of interconnected processes of medical staff involved that accompany a patient’s journey through the healthcare facility. Replicating this behavior with process flow models in a discrete event simulation model is highly complex and therefore difficult to create while maintaining a high degree of precision. A framework is thus introduced which delivers an algorithm that allows to implement Multiple Participant Pathway Modeling (MPPM) under the consideration of Flexible Resource …


Multi-Citeria Framework For An Emergency Department In An Irish Hospital, Waleed Abo Hamad, Amr Arisha Dec 2012

Multi-Citeria Framework For An Emergency Department In An Irish Hospital, Waleed Abo Hamad, Amr Arisha

Conference papers

Health research is one of these priorities in every economy and through this research an emphasis will be put on translational research in the context of more sustainable and efficient healthcare system (translation of operations management practices to clinical applications). Healthcare systems in general and Emergency Departments in particular around the world are facing enormous challenges in meeting the increasingly conflicting objectives of providing wide accessibility and efficiency while delivering high quality and prompt services. The proposed framework integrates simulation modeling, balanced scorecard, and multi-criteria decision analysis aiming to provide a decision support system to emergency department managers. Simulation outputs …


Addressing The Need To Reform Construction Public Procurement In Ireland Through The Implementation Of Building Information Modelling, Barry Mcauley, Alan Hore, Roger West, Dermot Kehily Nov 2012

Addressing The Need To Reform Construction Public Procurement In Ireland Through The Implementation Of Building Information Modelling, Barry Mcauley, Alan Hore, Roger West, Dermot Kehily

Conference papers

The Irish AEC Sector is facing one of its most uncertain and challenging periods and will see major cuts in all areas of the economy in 2012. Despite this the Irish Government has announced a number of large capital expenditure investments which have resultantly become a lifeline to a struggling construction industry. In order to compete within the public works sector AEC businesses must operate within the Governments Capital Works Management Framework. The objectives of the framework include achieving cost certainty, value for money and more effective delivery and appropriate risk sharing. The framework remains an area of contention and …


Diagnosing Weakness In Basic Principles Of Electricity In Motor Apprentice Education In Ireland, Peter Kenny Nov 2012

Diagnosing Weakness In Basic Principles Of Electricity In Motor Apprentice Education In Ireland, Peter Kenny

Conference Papers

Many Motor trade apprentice students enter the later years of their studies ill prepared for the level of material encountered. This is due to several factors including the level and knowledge of basic electricity and electrical/electronic principles.

A lot of basic material in these areas has been covered during earlier years of their training but by the time they reach the final year of their apprenticeship (Phase 6) it is not safe to assume that they have a full grasp of the basics required.

We have developed a diagnostic test to measure the level of preparedness of these students. This …


Mixed Method Collaboration In The Built Environment, Dermot Kehily Nov 2012

Mixed Method Collaboration In The Built Environment, Dermot Kehily

Conference papers

The built environment discipline or inter-discipline is a relatively new field in academic research. Its subject matter however is based on the traditional disciplines of the construction and property industries. Determining your ontological position and epistemological approach based on the researchparadigm of one of these fields’ may not provide an adequate solution to your research objectives.This paper outlines that framing your research within the broader confines of the built environment; drawing from related fields in an integrated manner may provide a more successful outcome.Arguments whether the built environment is an academic discipline or even the range of subjects thatmake up …


Knowledge Development Through Reflective Practice, Dermot Kehily Nov 2012

Knowledge Development Through Reflective Practice, Dermot Kehily

Conference papers

This paper examines the development of knowledge through reflective practice and more specifically the development of the author’s knowledge as a result of engaging in reflection on an issue in the field of the author’s research interest. The author commences by consulting and analysing existing published research on reflective practice. The paper sets out the theory of reflective practice as documented by eminent authors in the field. The author addresses the concept of action learning and frames this process within Kolb’s (1976) experiential learning model, in an attempt to formulate a framework whereby his own research focus can be developed. …


A 2.45/5.8 Ghz Folded Monopole Antenna For Wlan Applications, Abraham Loutridis, Matthias John, Giuseppe Ruvio, Max Ammann Nov 2012

A 2.45/5.8 Ghz Folded Monopole Antenna For Wlan Applications, Abraham Loutridis, Matthias John, Giuseppe Ruvio, Max Ammann

Conference Papers

A probe-fed printed folded monopole antenna for WLAN applications is presented. The antenna operates at 2.45 GHz and 5.8 GHz, is compact and has omni-directional characteristics in both bands. A parametric study of key geometrical parameters is reported.


Circularly Polarized Terminal Antennas For Emerging Wireless Systems, Max Ammann, Xiulong Bao, Adam Narbudowicz Nov 2012

Circularly Polarized Terminal Antennas For Emerging Wireless Systems, Max Ammann, Xiulong Bao, Adam Narbudowicz

Conference Papers

Several types of omni-directional Circularly Polarized (CP) antennas are presented, which are employed by three different types of feedlines: Coplanar Waveguide (CPW) fed, Microstrip fed, and Differential-fed, to achieve omni-directional CP performances. The Dual-frequency Omni-directional CP antenna is proposed by using slot and inductor embedded into radiated patches. These omnidirectional CP antennas have potential application on GPS, WLAN and RFID systems.


Integration Of Inverted-F Antenna With Solar Cell Substitute, Oisin O’Conchubhair, Patrick Mcevoy, Max Ammann, Giuseppe Ruvio Nov 2012

Integration Of Inverted-F Antenna With Solar Cell Substitute, Oisin O’Conchubhair, Patrick Mcevoy, Max Ammann, Giuseppe Ruvio

Conference Papers

A study into the effect of a solar cell lattice on the performance of an Inverted-F antenna is presented. An FR-4 substrate with a lattice of copper electrodes printed on one side and a solid copper ground plane on the other is used to represent a polycrystalline solar cell. The effect of the lattice orientation on the performance of the Inverted-F antenna is discussed.


Real-Time Prediction System Of Bathing Water Quality At Bray, Co. Wicklow, Ireland, Zeinab Bedri, John O'Sullivan, Aisling Corkery, Louise Deering, Katalin Demeter, Wim Meijer, Gregory O'Hare, Bartholomew Masterson Nov 2012

Real-Time Prediction System Of Bathing Water Quality At Bray, Co. Wicklow, Ireland, Zeinab Bedri, John O'Sullivan, Aisling Corkery, Louise Deering, Katalin Demeter, Wim Meijer, Gregory O'Hare, Bartholomew Masterson

Conference papers

Variations in water quality at recreational bathing beaches can have significant impacts with respect to compliance with related water quality standards, such as Directive 76/160/EEC. The “Blue Flag” award which bases its water quality standards upon the guideline E.coli levels of Directive 76/160/EEC, has become the measure of recreational value of bathing areas. Loss of such designations can have significant impacts with respect to local tourist economies. A revised Bathing Water Directive (Directive 2006/7/EC) came into force in 2006 and will supersede the existing 1976 Directive with effect from December 2014.

The revised Directive gives stronger focus on the protection …


Capacity Planning For Elderly Care In Ireland Using Simulation Modeling, Mohamed Ragab, Waleed Abo Hamad, Amr Arisha Nov 2012

Capacity Planning For Elderly Care In Ireland Using Simulation Modeling, Mohamed Ragab, Waleed Abo Hamad, Amr Arisha

Conference papers

Global population aging is creating an immense pressure on healthcare facilities making them unable to cope with the growing demand for elderly healthcare services. Current demand-supply gaps result in prolonged waiting times for patients and substantial cost burdens for healthcare systems due to delayed discharges. This paper describes a project aimed at presenting modeling and simulation to address elderly care pathways within the Irish healthcare sector. The management of frail patients admitted to acute hospitals and the introduction of the new intermediate care beds are alternative interventions that healthcare executives are interested in simulating to examine their impact on the …


Reducing Life Cycle Impacts Of The Existing Irish Housing Stock., Albert Famuyibo Nov 2012

Reducing Life Cycle Impacts Of The Existing Irish Housing Stock., Albert Famuyibo

Doctoral

Abstract

Despite the importance of addressing the challenges of the 2020 emissions reduction targets of both the European Union (EU) and Ireland, current residential emissions policies have focused mainly on the few existing studies that are primarily used to predict end-use energy and CO2 emissions savings. To allow all energy and emissions across life cycle phases to be evaluated, a process-based life cycle analysis (LCA) hybrid model was developed with the aim of determining the extent of reductions in resource consumption, greenhouse gas (GHG) emissions and costs of maintaining the existing Irish housing stock.

Thirteen representative archetypes of the …


Bs News November/December Nov 2012

Bs News November/December

Building Services Engineering

No abstract provided.


The Characterisation And Numerical Modelling Of Viscoelastic Polyurethane Foams For Use In Custom Wheelchair Seating, Conor Briody Nov 2012

The Characterisation And Numerical Modelling Of Viscoelastic Polyurethane Foams For Use In Custom Wheelchair Seating, Conor Briody

Doctoral

Viscoelastic polyurethane foam is widely used in wheelchair cushions as it offers good pressure relieving capabilities. However, the behaviour of this material is largely un-quantified, by comparison with conventional elastomeric materials.
Consequently, in many cases, inadequate cushioning is provided to wheelchair
users with complex seating requirements. This thesis characterises and
numerically models viscoelastic polyurethane foam.
Temperature-dependent static compression and simple shear test procedures are conducted on a range of viscoelastic polyurethane foams and selected results are utilised to identify Ogden Hyperfoam material model parameters. Time-dependent creep and stress relaxation test procedures are conducted and test results are used in conjunction …


The Characterisation And Numerical Modelling Of Viscoelastic Polyurethane Foams For Use In Custom Wheelchair Seating., Conor Briody Nov 2012

The Characterisation And Numerical Modelling Of Viscoelastic Polyurethane Foams For Use In Custom Wheelchair Seating., Conor Briody

Doctoral

Viscoelastic polyurethane foam is widely used in wheelchair cushions as it offers good pressure relieving capabilities. However, the behaviour of this material is largely un-quantified, by comparison with conventional elastomeric materials. Consequently, in many cases, inadequate cushioning is provided to wheelchair users with complex seating requirements. This thesis characterises and numerically models viscoelastic polyurethane foam. Temperature-dependent static compression and simple shear test procedures are conducted on a range of viscoelastic polyurethane foams and selected results are utilised to identify Ogden Hyperfoam material model parameters. Time-dependent creep and stress relaxation test procedures are conducted and test results are used in conjunction …


Voltage Flicker Evaluation For Wave Energy Converters – Assessment Guidelines, Fergus Sharkey, Elva Bannon, Joe Macenri, Kevin Gaughan, Michael Conlon Oct 2012

Voltage Flicker Evaluation For Wave Energy Converters – Assessment Guidelines, Fergus Sharkey, Elva Bannon, Joe Macenri, Kevin Gaughan, Michael Conlon

Conference papers

Voltage flicker is a power quality problem caused by regularly oscillating active and reactive power either from a load or generator. The regular power oscillations induce a voltage change at the grid connection which is proportional to the amplitude of the power oscillation and at the same frequency. The impedance of the grid (grid strength) at the point of connection is a factor in the amplitude of the voltage oscillation. The frequency band of interest for flicker evaluation is from 0.01-20Hz, and is most severe at 8.8Hz. The frequency of the primary resource for wave energy converters lies within this …


Practical Analysis Of Key Electrical Interfaces For Wave Energy Converter Arrays, Fergus Sharkey, Michael Conlon, Kevin Gaughan Oct 2012

Practical Analysis Of Key Electrical Interfaces For Wave Energy Converter Arrays, Fergus Sharkey, Michael Conlon, Kevin Gaughan

Conference papers

The authors have previously outlined a proposed path for the development of electrical networks for deepwater wave farms. This path broadly followed that of offshore wind farms as the least cost solution. The main differences between wind farm and wave farm electrical networks were identified as the method of installation and maintenance and the components at the WEC interface with the electrical network. Components such as dynamic cables, submarine connectors, submarine switchgear all form part of these interfaces. This paper examines the key electrical interfaces for WEC arrays such as the dynamic cable to WEC interface, dynamic cable to static …


Design And Test Of A Linear Switched Reluctance Generator For Use In Wave-Energy Applications, Garret Brady, Cathal O'Loughlin, John Massey, David Griffiths, Carlos Villegas Oct 2012

Design And Test Of A Linear Switched Reluctance Generator For Use In Wave-Energy Applications, Garret Brady, Cathal O'Loughlin, John Massey, David Griffiths, Carlos Villegas

Conference Papers

This paper describes the design of a double-sided linear switched reluctance generator for use in wave energy applications, and the build and test of a working bench-scale prototype. Beginning with a standard shape, the development of the design, from concept to detail, is presented. Numerical simulation results – magnetic, mechanical and electrical – inform the detailed design. Construction of the generator and test rig is described. Experimental results give good agreement with simulation predictions.


Purchasing Green Transport And Logistics Services: Implications For Small Business, Pietro Evangelista, Maria Huge-Brodin, Karin Isaksson, Edward Sweeney Oct 2012

Purchasing Green Transport And Logistics Services: Implications For Small Business, Pietro Evangelista, Maria Huge-Brodin, Karin Isaksson, Edward Sweeney

Articles

Considering its strong environmental impact, logistics plays a critical role in green supply chain management. It provides strategic links in the supply chain and is an essential function in the delivery of green products to the consumer. There is a general consensus on the fact that more environmentally sustainable companies may be achieved only if transport and logistics activities also become greener. To achieve this objective, buyer companies need to incorporate green considerations in the purchasing of transport and logistics services. This appears particularly challenging for small and medium sized enterprises (SMEs) because of their traditional lack of managerial, organisational …


The Rhetoric And Reality Of Supply Chain Management In Irish Business, Edward Sweeney Oct 2012

The Rhetoric And Reality Of Supply Chain Management In Irish Business, Edward Sweeney

Practitioner Journals

A strong focus of NITL’s research activity is on monitoring the extent to which SCM principles and concepts are adopted by organisations based in Ireland. For more than a decade this work has aimed to develop a profile of SCM adoption, as well as identifying some of the critical success factors and barriers influencing firms in their attempts to improve supply chain capability and performance. This article explains the role of SCM in Ireland’s economic recovery and provides an overview of NITL’s latest findings in relation to the adoption of SCM practices by firms in Ireland.