Open Access. Powered by Scholars. Published by Universities.®

Electrical and Electronics Commons

Open Access. Powered by Scholars. Published by Universities.®

Technological University Dublin

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 31 - 60 of 270

Full-Text Articles in Electrical and Electronics

Swarm Electrification: A Comprehensive Literature Review, Stephen Sheridan, Keith Sunderland, Jane Courtney Jan 2023

Swarm Electrification: A Comprehensive Literature Review, Stephen Sheridan, Keith Sunderland, Jane Courtney

Articles

In the global North, the need to decarbonize power generation is well documented and the challenges faced are endemic to the design of the electrical grids. With networks relying on centralized generation, it can be difficult to replace fossil-fuel power plants with renewable energy sources as generation may be intermittent causing grid instability when there is no ‘spinning reserve’ [1]. In parts of the global south, however, many under-electrified nations have high levels of solar irradiance. This, combined with falling prices for solar panels, is allowing for alternative paths to electrification from costly grid extensions and has resulted in grids …


Distributed Intermittent Fault Diagnosis In Wireless Sensor Network Using Likelihood Ratio Test, Bhabani Sankar Gouda, Meenakshi Panda, Trilochan Panigrahi, Sudhakar Das, Bhargav Appasani, Omprakash Acharya, Hossam Zawbaa, Salah Kamel Jan 2023

Distributed Intermittent Fault Diagnosis In Wireless Sensor Network Using Likelihood Ratio Test, Bhabani Sankar Gouda, Meenakshi Panda, Trilochan Panigrahi, Sudhakar Das, Bhargav Appasani, Omprakash Acharya, Hossam Zawbaa, Salah Kamel

Articles

In current days, sensor nodes are deployed in hostile environments for various military and commercial applications. Sensor nodes are becoming faulty and having adverse effects in the network if they are not diagnosed and inform the fault status to other nodes. Fault diagnosis is difficult when the nodes behave faulty some times and provide good data at other times. The intermittent disturbances may be random or kind of spikes either in regular or irregular intervals. In literature, the fault diagnosis algorithms are based on statistical methods using repeated testing or machine learning. To avoid more complex and time consuming repeated …


Intelligent Beam Steering For Wireless Communication Using Programmable Metasurfaces, Nouman Ashraf, Taqwa Saeed, Hamidreza Taghvaee, Sergi Abadal, Vasos Vasos, Christos Liaskos Christos Liaskos, Andreas Pitsillides, Marios Lestas Marios Lestas Jan 2023

Intelligent Beam Steering For Wireless Communication Using Programmable Metasurfaces, Nouman Ashraf, Taqwa Saeed, Hamidreza Taghvaee, Sergi Abadal, Vasos Vasos, Christos Liaskos Christos Liaskos, Andreas Pitsillides, Marios Lestas Marios Lestas

Articles

Future generations of wireless communications are envisioned to provide several Gbps data rates per user for billions of users simultaneously [1]. The proliferation of billions of Internet of Things (IoT) devices in various industries has pushed wireless networks to their limits in terms of the required capacity to effectively communicate the vast amounts of data that are generated [2]. Moreover, the increasing number of IoT devices is changing mobile communication services from interpersonal communication to smart interconnection among billions of devices. 6G is expected to fulfill the requirements of a fully connected world and provide ubiquitous wireless connectivity for all …


Optical Properties Of Periodically And Aperiodically Nanostructured P-N Junctions, Z. Taliashvili, E Łusakowska E Łusakowska, S. Chusnutdinow, A. Tavkhelidze, L. Jangidze, S. Sikharulidze, Nima Ghadiri, Z. Chubinidze, R. Melkadze Jan 2023

Optical Properties Of Periodically And Aperiodically Nanostructured P-N Junctions, Z. Taliashvili, E Łusakowska E Łusakowska, S. Chusnutdinow, A. Tavkhelidze, L. Jangidze, S. Sikharulidze, Nima Ghadiri, Z. Chubinidze, R. Melkadze

Articles

Recently, semiconductor nanograting layers have been introduced and their optical properties have been studied. Spectroscopic ellipsometry has shown that nanograting significantly modifies the dielectric function of c-Si layers. Photoluminescence spectroscopy reveals the emergence of an emission band with a remarkable peak structure. It has been observed that nanograting also alters the electronic and magnetic properties. In this study, we investigate the quantum efficiency and spectral response of Si p-n junctions fabricated using subwavelength grating layers and aperiodically nanostructured layers.


Exploiting Multimode Antennas For Mimo And Aoa Estimation In Size-Constrained Iot Devices, Abel Zandamela, Alessandro Chiumento Alessandro Chiumento, Alessandro Chiumento, Nicola Marchetti, Max Ammann, Adam Narbudowicz Jan 2023

Exploiting Multimode Antennas For Mimo And Aoa Estimation In Size-Constrained Iot Devices, Abel Zandamela, Alessandro Chiumento Alessandro Chiumento, Alessandro Chiumento, Nicola Marchetti, Max Ammann, Adam Narbudowicz

Articles

This work proposes compact multimode Multiple-Input–Multiple-Output (MIMO) antennas for Angle of Arrival (AoA) estimation in miniaturized Internet of Things (IoT) systems. The method excites different orthogonal radiating modes (TM 21 , TM 02 , and TM 31 modes) for beamforming capabilities, and the AoA performance is investigated using the Multiple Signal Classification (MUSIC) algorithm, executed using numerical and experimental data. The technique is tested at 2.238GHz , while using an antenna diameter


Co-Design Of An Interactive Wellness Park: Exploring Design Requirements For A Multimodal Outdoor Physical Web Installation With Older Adults, Fatima Badmos Jan 2023

Co-Design Of An Interactive Wellness Park: Exploring Design Requirements For A Multimodal Outdoor Physical Web Installation With Older Adults, Fatima Badmos

Academic Posters Collection

The global demographic landscape is experiencing a notable shift, characterised by a growing proportion of adults over 60. According to projections, the proportion of individuals aged 60 and above is expected to reach one-sixth of the global population by 2030. Furthermore, by 2050, this demographic is projected to exceed a staggering two billion people. Amidst this shift, there is an urgent need to develop interactive and innovative solutions to address older adults' unique challenges, particularly in outdoor physical activity.

A co-design methodology involving older adults’ participation from the idea generation to the application development process will be adopted to address …


Zno Varistors – The Ideal Microstructure And Characteristics, And Methods Investigated And Developed To Achieve These, Maura Kelleher Jan 2023

Zno Varistors – The Ideal Microstructure And Characteristics, And Methods Investigated And Developed To Achieve These, Maura Kelleher

Books/Book Chapters

ZnO-Bi2O3-Sb2O3 varistors have been extensively studied since their discovery 5 decades ago. Their function in protecting increasingly sensitive electronic components by absorbing random surges of energy is even more important today. Also, the metal oxides from which they are made from are becoming even more precious. Their electrical characteristics are highly dependent on their microstructural characteristics which are highly dependent on their composition and methods used. The purpose of this article is to explain the ideal microstructure required to obtain the ideal electrical characteristics, the powder preparation methods investigated and developed to achieve it, and some future directions are outlined.


Load-Adjusted Prediction For Proactive Resource Management And Video Server Demand Profiling, Obinna Izima, Ruairí De Fréin Jul 2022

Load-Adjusted Prediction For Proactive Resource Management And Video Server Demand Profiling, Obinna Izima, Ruairí De Fréin

Articles

To lower costs associated with providing cloud resources, a network manager would like to estimate how busy the servers will be in the near future. This is a necessary input in deciding whether to scale up or down computing requirements. We formulate the problem of estimating cloud computational requirements as an integrated framework comprising of a learning and an action stage. In the learning stage, we use Machine Learning (ML) models to predict the video Quality of Delivery (QoD) metric for cloud-hosted servers and use the knowledge gained from the process to make resource management decisions during the action stage. …


Optimization Based On Movable Damped Wave Algorithm For Design Of Photovoltaic/ Wind/ Diesel/ Biomass/ Battery Hybrid Energy Systems, Mohammed Kharrich, Salah Kamel, Mamdouh Abdel-Akher, Ahmad Eid, Hossam Zawbaa, Jonghoon Kim Jan 2022

Optimization Based On Movable Damped Wave Algorithm For Design Of Photovoltaic/ Wind/ Diesel/ Biomass/ Battery Hybrid Energy Systems, Mohammed Kharrich, Salah Kamel, Mamdouh Abdel-Akher, Ahmad Eid, Hossam Zawbaa, Jonghoon Kim

Articles

The actual energetic situation has several challenges such as pollution, the rarefaction of fossil fuel and the dangers of nuclear. Renewable sources are proposed as a solution and suggested, such as a cost-effectiveness system. The paper deals with the problem of feeding a domestic load with electricity which should respect the ecologies factors, so this work is a design problem of the hybrid renewable energy systems; PV/biomass, PV/diesel/battery, PV/wind/diesel/battery, and wind/diesel/battery to choose the best one of them which feed the load with the lowest cost. The study’s goal is to design a microgrid system by the minimization of the …


Optimal Design Of Photovoltaic, Biomass, Fuel Cell, Hydrogen Tank Units And Electrolyzer Hybrid System For A Remote Area In Egypt, Abd El-Sattar Abd El-Sattar, Salah Kamel, Hamdy M. Sultan, Hossam Zawbaa, Francisco Jurado Jan 2022

Optimal Design Of Photovoltaic, Biomass, Fuel Cell, Hydrogen Tank Units And Electrolyzer Hybrid System For A Remote Area In Egypt, Abd El-Sattar Abd El-Sattar, Salah Kamel, Hamdy M. Sultan, Hossam Zawbaa, Francisco Jurado

Articles

In this paper, a new isolated hybrid system is simulated and analyzed to obtain the optimal sizing and meet the electricity demand with cost improvement for servicing a small remote area with a peak load of 420 kW. The major configuration of this hybrid system is Photovoltaic (PV) modules, Biomass gasifier (BG), Electrolyzer units, Hydrogen Tank units (HT), and Fuel Cell (FC) system. A recent optimization algorithm, namely Mayfly Optimization Algorithm (MOA) is utilized to ensure that all load demand is met at the lowest energy cost (EC) and minimize the greenhouse gas (GHG) emissions of the proposed system. The …


Enhanced Chaotic Manta Ray Foraging Algorithm For Function Optimization And Optimal Wind Farm Layout Problem, Fatima Dadqaq, Rachid Ellaia, Mohammed Ouassaid, Hossam Zawbaa, Salah Kamel Jan 2022

Enhanced Chaotic Manta Ray Foraging Algorithm For Function Optimization And Optimal Wind Farm Layout Problem, Fatima Dadqaq, Rachid Ellaia, Mohammed Ouassaid, Hossam Zawbaa, Salah Kamel

Articles

Manta ray foraging optimization (MRFO) algorithm is relatively a novel bio-inspired optimization technique directed to given real-world engineering problems. In this present work, wind turbines layout (WTs) inside a wind farm is considered a real nonlinear optimization problem. In spite of the better convergence of MRFO, it gets stuck into local optima for large problems. The chaotic sequences are among the performed techniques used to tackle this shortcoming and improve the global search ability. Therefore, ten chaotic maps have been embedded into MRFO. To affirm the performance of the suggested chaotic approach CMRFO, it was First assessed using the IEEE …


The Environmental Aspects Of Renewable Energy Consumption And Structural Change In Sweden: A New Perspective From Wavelet-Based Granger Causality Approach, Tomiwa Sunday Adebayo, Ridwan Lanre Ibrahim, Ephraim Bonah Agyekum, Hossam Zawbaa, Salah Kamel Jan 2022

The Environmental Aspects Of Renewable Energy Consumption And Structural Change In Sweden: A New Perspective From Wavelet-Based Granger Causality Approach, Tomiwa Sunday Adebayo, Ridwan Lanre Ibrahim, Ephraim Bonah Agyekum, Hossam Zawbaa, Salah Kamel

Articles

The current paper assessed the time-frequency analysis interrelationship between CO2 emissions and financial development, economic growth, renewable energy use, structural change, and non-renewable energy use in Sweden. We utilized a quarterly dataset stretching from 1980-2019. In order to unlock these interrelationships, we leverage wavelet tools (wavelet-based Granger causality and wavelet coherence). The wavelet-based Granger causality (WGC) test accounts for the issue of multiple time scales in a time series analysis. Another uniqueness of the WGC lies in its resistance to distribution assumption and misspecification in a time series model. Additionally, the wavelet coherence estimator instantaneously evaluates correlation and causality among …


Efficient Flatness Based Energy Management Strategy For Hybrid Supercapacitor/Lithium-Ion Battery Power System, Salam J. Yaqoob, Seydali Ferahtia, Adel Obed, Hegazy Rezk, Naseer Tawfeeq Alwan, Hossam Zawbaa, Salah Kamel Jan 2022

Efficient Flatness Based Energy Management Strategy For Hybrid Supercapacitor/Lithium-Ion Battery Power System, Salam J. Yaqoob, Seydali Ferahtia, Adel Obed, Hegazy Rezk, Naseer Tawfeeq Alwan, Hossam Zawbaa, Salah Kamel

Articles

This article offers a flatness theory-based energy management strategy (FEMS) for a hybrid power system consisting of a supercapacitor (SC) and lithium-ion battery. The proposed FEMS intends to allocate the power reference for the DC/DC converters of both the battery and SC while attaining higher effciency and stable DC bus voltage. First, the entire system model is analyzed theoretically under the differential flatness approach to reduce the model order as a at system. Second, the proposed FEMS is validated under different load conditions using MATLAB/Simulink. Thus, this FEMS provides high-quality energy to the load and reduces the fluctuations in the …


Hosting A Community-Based Local Electricity Market In A Residential Network, Aziz Saif, Shafi K. Khadem, Michael Conlon, Brian Norton Jan 2022

Hosting A Community-Based Local Electricity Market In A Residential Network, Aziz Saif, Shafi K. Khadem, Michael Conlon, Brian Norton

Articles

This paper presents the potential of building a local electricity market (LEM) to boost the deployment of the local energy communities, centred around active customers with distributed energy resources (DERs). To conduct a comprehensive and detailed study on different cases with reduced computational burdens, this paper adopts a simplified modelling approach where the market and network model simulations are performed in a cascaded, decoupled fashion. This allows achieving the optimal LEM output for the energy community with different DER assets that are not bounded by the network constraints. The investigation involves quantifying the benefits brought by LEM to energy communities …


A Survey Of Machine Learning Techniques For Video Quality Prediction From Quality Of Delivery Metrics, Obinna Izima, Ruairí De Fréin, Ali Malik Nov 2021

A Survey Of Machine Learning Techniques For Video Quality Prediction From Quality Of Delivery Metrics, Obinna Izima, Ruairí De Fréin, Ali Malik

Articles

A growing number of video streaming networks are incorporating machine learning (ML) applications. The growth of video streaming services places enormous pressure on network and video content providers who need to proactively maintain high levels of video quality. ML has been applied to predict the quality of video streams. Quality of delivery (QoD) measurements, which capture the end-to-end performances of network services, have been leveraged in video quality prediction. The drive for end-to-end encryption, for privacy and digital rights management, has brought about a lack of visibility for operators who desire insights from video quality metrics. In response, numerous solutions …


Optimal Placement Of Fuses And Switches In Active Distribution Networks Using Value-Based Minlp, N. Gholizadeh, S.H. Hosseinian, M. Abedi, Hamed Nafisi, P. Siano Sep 2021

Optimal Placement Of Fuses And Switches In Active Distribution Networks Using Value-Based Minlp, N. Gholizadeh, S.H. Hosseinian, M. Abedi, Hamed Nafisi, P. Siano

Articles

Contingency conditions in distribution networks create financial losses for different parts of the system including electricity customers, electricity retailers, distributed generation (DG) units, etc. Therefore, protective device allocation methods have been introduced in recent years to enhance the reliability of the power system. In this study, a new formulation is proposed to find the optimal places of sectionalizing switches and fuses while taking the financial loss of both electricity customers and DG units into account. The current method has the flexibility to consider DG effect on any location of the network and its islanded operation in case of contingencies. Moreover, …


Grammatical Evolution For Detecting Cyberattacks In Internet Of Things Environments, Hasanen Alyasiri, John Clark, Ali Malik, Ruairí De Fréin Jul 2021

Grammatical Evolution For Detecting Cyberattacks In Internet Of Things Environments, Hasanen Alyasiri, John Clark, Ali Malik, Ruairí De Fréin

Conference papers

The Internet of Things (IoT) is revolutionising nearly every aspect of modern life, playing an ever greater role in both industrial and domestic sectors. The increasing frequency of cyber-incidents is a consequence of the pervasiveness of IoT. Threats are becoming more sophisticated, with attackers using new attacks or modifying existing ones. Security teams must deal with a diverse and complex threat landscape that is constantly evolving. Traditional security solutions cannot protect such sys- tems adequately and so researchers have begun to use Machine Learning algorithms to discover effective defence systems. In this paper, we investigate how one approach from the …


Flying Free: A Research Overview Of Deep Learning In Drone Navigation Autonomy, Thomas Lee, Susan Mckeever, Jane Courtney Jun 2021

Flying Free: A Research Overview Of Deep Learning In Drone Navigation Autonomy, Thomas Lee, Susan Mckeever, Jane Courtney

Articles

With the rise of Deep Learning approaches in computer vision applications, significant strides have been made towards vehicular autonomy. Research activity in autonomous drone navigation has increased rapidly in the past five years, and drones are moving fast towards the ultimate goal of near-complete autonomy. However, while much work in the area focuses on specific tasks in drone navigation, the contribution to the overall goal of autonomy is often not assessed, and a comprehensive overview is needed. In this work, a taxonomy of drone navigation autonomy is established by mapping the definitions of vehicular autonomy levels, as defined by the …


An Lpc Pole Processing Method For Enhancing The Identification Of Dominant Spectral Features, Jin Xu, Mark Davis, Ruairí De Fréin May 2021

An Lpc Pole Processing Method For Enhancing The Identification Of Dominant Spectral Features, Jin Xu, Mark Davis, Ruairí De Fréin

Articles

This paper proposes a new time-resolved spectral analysis method based on a modification to the linear predictive coding (LPC) method for enhancing the identification of the dominant frequencies of a signal. The method described here is based on a z-plane analysis of the LPC poles. These poles are used to produce a series of reduced order filter transfer functions which can accurately identify and estimate the frequency of the dominant spectral features. The standard LPC method has been shown to suffer from a sensitivity to noise and its performance is dependent on the filter order. The proposed method can …


A Two-Level Information Modelling Translation Methodology And Framework To Achieve Semantic Interoperability In Constrained Geoobservational Sensor Systems, Paul Stacey Jan 2021

A Two-Level Information Modelling Translation Methodology And Framework To Achieve Semantic Interoperability In Constrained Geoobservational Sensor Systems, Paul Stacey

Doctoral

As geographical observational data capture, storage and sharing technologies such as in situ remote monitoring systems and spatial data infrastructures evolve, the vision of a Digital Earth, first articulated by Al Gore in 1998 is getting ever closer. However, there are still many challenges and open research questions. For example, data quality, provenance and heterogeneity remain an issue due to the complexity of geo-spatial data and information representation.

Observational data are often inadequately semantically enriched by geo-observational information systems or spatial data infrastructures and so they often do not fully capture the true meaning of the associated datasets. Furthermore, data …


Day-Ahead Offering Strategy In The Market For Concentrating Solar Power Considering Thermoelectric Decoupling By A Compressed Air Energy Storage, Shitong Sun, S. Mahdi Kazemi-Razi, Lisa G. Kaigutha, Mousa Marzband, Hamed Nafisi, Ameena Saad Al-Sumaiti Jan 2021

Day-Ahead Offering Strategy In The Market For Concentrating Solar Power Considering Thermoelectric Decoupling By A Compressed Air Energy Storage, Shitong Sun, S. Mahdi Kazemi-Razi, Lisa G. Kaigutha, Mousa Marzband, Hamed Nafisi, Ameena Saad Al-Sumaiti

Articles

Due to limited fossil fuel resources, a growing increase in energy demand and the need to maintain positive environmental effects, concentrating solar power (CSP) plant as a promising technology has driven the world to find new sustainable and competitive methods for energy production. The scheduling capability of a CSP plant equipped with thermal energy storage (TES) surpasses a photovoltaic (PV) unit and augments the sustainability of energy system performance. However, restricting CSP plant application compared to a PV plant due to its high investment is a challenging issue. This paper presents a model to assemble a combined heat and power …


Using Case Studies In Engineering Ethics Education: The Case For Immersive Scenarios Through Stakeholder Engagement And Real Life Data, Diana Adela Martin, Eddie Conlon, Brian Bowe Jan 2021

Using Case Studies In Engineering Ethics Education: The Case For Immersive Scenarios Through Stakeholder Engagement And Real Life Data, Diana Adela Martin, Eddie Conlon, Brian Bowe

Articles

Our contribution is part of a broader study conducted in cooperation with the national accreditation body Engineers Ireland that examined the conceptualisation and education of ethics in engineering programmes in Ireland. The paper is a qualitative examination of the use of case studies in engineering ethics education and includes 23 engineering programmes from 6 higher education institutions in Ireland. The qualitative study aims to determine (RQ1) how cases are selected, (RQ2) the goals envisioned for engineering ethics case instruction, (RQ3) the characteristics of the scenarios employed and (RQ4) the preferred application by instructors. A first finding notes the diverse set …


Predicting Quality Of Delivery Metrics For Adaptive Video Codec Sessions, Obinna Izima, Ruairí De Fréin, Mark Davis Nov 2020

Predicting Quality Of Delivery Metrics For Adaptive Video Codec Sessions, Obinna Izima, Ruairí De Fréin, Mark Davis

Conference papers

Predicting video quality will continue to be an active area of research given the dominance of video traffic for years to come. Network service practitioners that are poised to handle the strain on the existing limited bandwidth constraints are better placed to be SLA-compliant. The dynamic and time-varying nature of cloud-hosted services require improved techniques to realize accurate models of the systems. To address this challenge: (1) we propose Codec-aware Network Adaptation Agent (cNAA), an online light-weight data learning engine that achieves accurate and correct predictions of quality of delivery (QoD) metrics, namely jitter for video services. cNAA achieves this …


Remedying Sound Source Separation Via Azimuth Discrimination And Re-Synthesis, Ruairí De Fréin Jun 2020

Remedying Sound Source Separation Via Azimuth Discrimination And Re-Synthesis, Ruairí De Fréin

Conference papers

Commercially recorded music since the 1950s has been mixed down from many input sound sources to a two-channel reproduction of these sources. The effect of this approach is to assign sources to locations in a stereo field using a pan-position for each source. The Adress algorithm is a popular way of extracting individual music sound sources from a stereo mixture. A drawback of the Adress algorithm is that when time-frequency components in the stereo mixture are shared between two or more sources, calculating the inter-aural intensity scaling parameter for each source for that time-frequency component is challenging. We show how …


Remedying Sound Source Separation Via Azimuth Discrimination And Re-Synthesis, Ruairí De Fréin Jun 2020

Remedying Sound Source Separation Via Azimuth Discrimination And Re-Synthesis, Ruairí De Fréin

Conference papers

Commercially recorded music since the 1950s has been mixed down from many input sound sources to a two- channel reproduction of these sources. The effect of this approach is to assign sources to locations in a stereo field using a pan- position for each source. The Adress algorithm is a popular way of extracting individual music sound sources from a stereo mixture. A drawback of the Adress algorithm is that when time- frequency components in the stereo mixture are shared between two or more sources, calculating the inter-aural intensity scaling parameter for each source for that time-frequency component is challenging. …


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 Jan 2020

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 …


Calibration To Mitigate Near-Field Antennas Effects For A Mimo Radar Imaging System, Ha Hoang, Matthias John, Patrick Mcevoy, Max Ammann Jan 2020

Calibration To Mitigate Near-Field Antennas Effects For A Mimo Radar Imaging System, Ha Hoang, Matthias John, Patrick Mcevoy, Max Ammann

Articles

A calibration method for a high-resolution hybrid MIMO turntable radar imaging system is presented. A line of small metal spheres is employed as a test pattern in the calibration process to measure the position shift caused by undesired antenna effects. The unwanted effects in the antenna near-field responses are analysed, modelled and significantly mitigated based on the symmetry and differences in the responses of the MIMO configuration.


Accounting For The Local Field When Determining The Dielectric Loss Spectra Of Metals In The Region Of The Frequencies Of Volume, Surface And Localized Plasmon Oscillations, Tatiana Perova, Igor Shaganove, Kevin Berwick Jan 2020

Accounting For The Local Field When Determining The Dielectric Loss Spectra Of Metals In The Region Of The Frequencies Of Volume, Surface And Localized Plasmon Oscillations, Tatiana Perova, Igor Shaganove, Kevin Berwick

Articles

The optical constant of bulk metal is used to determine the dispersion of the local field under one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) confinement. 3D confinement, expressed as ε mic 2 (ω3D), corresponds to the dielectric loss spectra of spherical particles with a diameter, d, much less than the wavelength of the beam used to measure the spectrum (d << λ). Excellent agreement with the results of Mie theory and experimental data for solid colloids within alkali halide crystals was observed. The function expressed as ε mic 2 (ω1D) allows the measurement of spectral micro-characteristics in the frequency range of the longitudinal collective motion of the free electrons. This corresponds to the spectrum of dielectric losses of bulk plasma oscillations. The function ε mic 2 (ω2D) describes the spectra of the dielectric losses of surface plasma oscillations in thin metal films. It is shown that the peak positions of ε mic 2 (ω3D), ε mic 2 (ω2D) and ε mic 2 (ω1D) spectra for simple metals, viz. alkali metals as well as Al, Be, Mg, Ga, In, Sn and Si, are in agreement with experimental results from electron-energy-loss spectroscopy and various optical techniques.


Optimal Sizing Of Energy Storage With Embedded Wind Power Generation, Nicholas Roche, Jane Courtney Jan 2020

Optimal Sizing Of Energy Storage With Embedded Wind Power Generation, Nicholas Roche, Jane Courtney

Articles

Energy storage technologies are key to increased penetration of renewable energies on the distribution system. Not only do they increase availability of energy, but they contribute to the overall reliability of the system. However, the cost of large-scale storage systems can often be prohibitive, and storage needs to be sized appropriately, both to fill the energy gaps inevitable in renewable energies such as wind and to minimize costs. In this work, a Monte Carlo Simulation is performed to optimally size an energy storage system while minimizing overall system cost. 30 years of historical wind speed data are used to model …


Color Variation Of The Up-Conversion Luminescence In Er3+-Yb3+Co-Doped Lead Germanate Glasses And Microsphere Integrated Devices, Meng Zhang, Ke Tian, Shunbin Wang, Libo Yuan, Gerald Farrell, Elfed Lewis, Pengfei Wang Jan 2020

Color Variation Of The Up-Conversion Luminescence In Er3+-Yb3+Co-Doped Lead Germanate Glasses And Microsphere Integrated Devices, Meng Zhang, Ke Tian, Shunbin Wang, Libo Yuan, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

Abstract—Lead germanate glass samples co-doped with different Er3+/Yb3+ concentrations were prepared and the color variation of the up-conversion emissions in these glasses was observed using a 980 nm laser pump. A practical optical integrated device based on Er3+ -Yb3+ co-doped lead germanate glass microsphere and a special fiber structure, consisting of single mode fiber (SMF), multimode fiber (MMF) and a suspended tricore hollow fiber (STCHF) is described. As the pump light is coupled into the microsphere from the cores suspended inside the STCHF, the microsphere fixed in the air hole of the STCHF is excited and the up-conversion emissions are …