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Articles 31 - 60 of 113
Full-Text Articles in Electrical and Electronics
A Survey Of Machine Learning Techniques For Video Quality Prediction From Quality Of Delivery Metrics, Obinna Izima, Ruairí De Fréin, Ali Malik
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
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, …
Flying Free: A Research Overview Of Deep Learning In Drone Navigation Autonomy, Thomas Lee, Susan Mckeever, Jane Courtney
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
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 …
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
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
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 …
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
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
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
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
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 …
Crystal-Field Engineering Of Ultrabroadband Mid-Infrared Emission In Co2+-Doped Nano-Chalcogenide Glass Composites, Xiasong Lu, Runan Zhang, Yindong Zhang, Shaoqian Zhang, Jing Ren, Lukas Strizik, Thomas Wagner, Gerald Farrell, Pengfei Wang
Crystal-Field Engineering Of Ultrabroadband Mid-Infrared Emission In Co2+-Doped Nano-Chalcogenide Glass Composites, Xiasong Lu, Runan Zhang, Yindong Zhang, Shaoqian Zhang, Jing Ren, Lukas Strizik, Thomas Wagner, Gerald Farrell, Pengfei Wang
Articles
unable and ultrabroadband mid-infrared (MIR) emissions in the range of 2.5–4.5 μm are firstly reported from Co2+-doped nano-chalcogenide (ChG) glass composites. The composites embedded with a variety of binary (ZnS, CdS, ZnSe) and ternary (ZnCdS, ZnSSe) ChG nanocrystals (NCs) can be readily obtained by a simple one-step thermal annealing method. They are highly transparent in the near- and mid-infrared wavelength region. Low-cost and commercially available Er3+-doped fiber lasers can be used as the excitation source. By crystal-field engineering of the embedded NCs through cation- or anion-substitution, the emission properties of Co2+ including its emission peak wavelength and bandwidth can be …
Impact Assessment Of High-Power Domestic Ev Charging Proliferation Of A Distribution Network, Arsalan Zaidi, Keith Sunderland, Michael Conlon
Impact Assessment Of High-Power Domestic Ev Charging Proliferation Of A Distribution Network, Arsalan Zaidi, Keith Sunderland, Michael Conlon
Articles
Transport electrification is becoming the mainstream as a means to improve efficiency, performance, andsustainability of transportation systems. Electrical vehicles (EVs) can help to de-carbonise the environment, but a downside isthe technical issues presented to the low-voltage distribution network. To quantify the stochastic nature of transport-affectedelectrification, probabilistic load flow is employed. Monte Carlo-based simulation is applied to accommodate the probabilisticuncertainties associated with variable EV charging patterns. This study considers high-power charging (up to 11 kW) at thedomestic level while monitoring power quality variations (voltage drop, voltage unbalance factor, voltage sag) standards. Thiswork focuses on the Irish and UK, distribution system operator's–transmission …
A Wide Frequency Scanning Printed Bruce Array Antenna With Bowtie And Semi-Circular Elements, Zeeshan Ahmed, Patrick Mcevoy, Max Ammann
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° …
Application Of Demand Response To Improve Voltage Regulation With High Dg Penetration, Chittesh Veni Chandran, Malabika Bassu, Keith Sunderland, Shivananda Pukhrem, João Catalão
Application Of Demand Response To Improve Voltage Regulation With High Dg Penetration, Chittesh Veni Chandran, Malabika Bassu, Keith Sunderland, Shivananda Pukhrem, João Catalão
Articles
The ability of a consumer friendly demand response based voltage control (DR-VC) program to improve the voltage regulation in a low voltage distribution network (LVDN) with high penetration of DG is investigated. The use of active and reactive power management to regulate the nodal voltage in a distribution network with simple incremental reduction algorithm, in conjunction with DR, is proposed as a solution for over voltage and undervoltage issues in the LVDN. The algorithm micromanages the load and generation in the network enabling the operator to utilize grid resources economically and efficiently while maintaining fairness between consumers with minimum inconvenience. …
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
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.
Saperi: Approaching Gender Gap Using Spatial Ability Training Week In High-School Context, Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, Anita Tabacco
Saperi: Approaching Gender Gap Using Spatial Ability Training Week In High-School Context, Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, Anita Tabacco
Articles
Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, and Anita Tabacco. 2020. SAperI: approaching gender gap using Spatial Ability training week in high-school context. In Eighth International Conference on Technological Ecosystems for Enhancing Multiculturality (TEEM’20), October 21–23, 2020, Salamanca, Spain. ACM, New York, NY, USA, 7 pages. https://doi.org/10.1145/3434780.3436577
Compact Broadband Triple-Ring Five-Port Reflectometer For Microwave Brain Imaging Applications, Toufiq Md Hossain, Mohd Faizal Jamlos, Mohd Aminudin Jamlos, Ping Jack Shoh, Siti Zuraidah Ibrahim, Muammar Mohamad Isa, Dominque M.M.-P. Schreurs, Adam Narbudowicz, Mohd Fairusham Ghazali
Compact Broadband Triple-Ring Five-Port Reflectometer For Microwave Brain Imaging Applications, Toufiq Md Hossain, Mohd Faizal Jamlos, Mohd Aminudin Jamlos, Ping Jack Shoh, Siti Zuraidah Ibrahim, Muammar Mohamad Isa, Dominque M.M.-P. Schreurs, Adam Narbudowicz, Mohd Fairusham Ghazali
Articles
The broadband five-port refectometer (FPR) is proposed using a triple-ring based technique. The design introduces a tapering in the inter-ring transmission lines (TLs), which provides additional degrees of freedom for optimization and contributes to increased bandwidth. The miniaturization strategy allows incorporating the third ring without signifcant size increase. In addition, a method for expressing the effective physical dimension of a planar symmetric FPR is also presented in an easily comprehensible way, which can be implemented for other symmetric planar junctions with more than four ports. The proposed design comprises three concentric rings with phase-shifting arrangements between the inter-ring TLs and …
Dc Side And Ac Side Cascaded Multilevel Inverter Topologies: A Comparative Study Due To Variation In Design Features, Shahab Sajedi, Michael Farrell, Malabika Basu
Dc Side And Ac Side Cascaded Multilevel Inverter Topologies: A Comparative Study Due To Variation In Design Features, Shahab Sajedi, Michael Farrell, Malabika Basu
Articles
This paper presents a comparative study between DC side and AC side cascaded topologies for the hybrid modular multilevel converter (MMC) which are becoming popular in recent years. A multilevel converter with half or full bridge sub modules connected across DC link is another alternative for high-voltage applications as it has the same number of sub modules and footprint as AC side cascaded topology with the same DC link voltage and AC side voltage. The compared AC side cascaded structure offers a two-level converter as the high voltage stage and cascaded H-bridge (which is full bridge) sub modules with electrically …
A Review Of Co2 Emission Reductions Due To Wind Turbines Using Energy Benchmarks: A Focus On The Irish Electrical Energy Market, Tony Kealy
Articles
The installed capacity of wind turbines in Ireland increased from a value of 2,250 MW in 2014 to 3,318 MW in 2017, a 43% increase in the four years, supported through climate mitigation policies. The main aim of this study is to determine if the increase in wind turbine installed capacity is impacting on efforts to reduce CO2 emissions. The study utilises a review methodology. The findings show that the steady rise in wind turbine installed capacity year-on-year is not reflected in the Irish CO2 g/kWh energy benchmark. The benchmark value was 457 g CO2/kWh in 2014 and 437 g …
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
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 …
Low-Cost Multimode Patch Antenna For Dual Mimo And Enhanced Localization Use, Adam Narbudowicz, Max Ammann
Low-Cost Multimode Patch Antenna For Dual Mimo And Enhanced Localization Use, Adam Narbudowicz, Max Ammann
Articles
This paper proposes a simple, low-cost multi-mode patch antenna combining good MIMO performance with precise Angle of Arrival (AoA) estimation. The AoA is based on the monopulse antenna concept, however, unlike in radar applications, the necessity for complex circuitry is replaced by the intrinsic properties of even and odd resonant patch modes. This capability is advantageous for future “Internet of Things” antennas, embedded into low-cost and size-constrained devices. The envelope correlation coefficient, measured in an anechoic chamber, is below 1.5 %, ensuring good MIMO performance. An exemplary addition to localization algorithm exploiting antenna properties is demonstrated.
Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann
Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann
Articles
Full duplex radios have become a topic of increased interest in the wireless communications community. As part of this development, many efforts were directed to passively decrease the self-interference level at the antenna outputs. However, in many proposed solutions transmission and reception occur through different propagation channels. This paper demonstrates and quantifies the negative impact of channel differentiation on pivotal applications of full-duplex radio, such as cognitive radio. Antenna designs used for self-interference suppression in full-duplex radio architectures are analyzed. In order to ensure that transmission and reception occur within the same propagation channel, the use of the envelope correlation …
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.
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 …
The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher
The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher
Articles
The different phase resolved partial discharge patterns, which can be recognized when a positive dc voltage containing a ripple due to a half-wave rectification is used are presented in this paper. Results are given from corona onset to the appearance of breakdown streamers. The outcomes are five different patterns, which represent the four stages of positive corona and their transition zones. Three of them are clearly identifiable with respect to patterns from other discharge sources that have already been reported for dc voltages containing a ripple. For an assessment of pattern formation discharge pulses as recorded at the test object …
The Effect Of The Local Field And Dipole-Dipole Interactions On The Absorption Spectra Of Noble Metals And The Plasmon Resonance Of Their Nanoparticles, I.I. Shaganov, T.S. Perova, Kevin Berwick
The Effect Of The Local Field And Dipole-Dipole Interactions On The Absorption Spectra Of Noble Metals And The Plasmon Resonance Of Their Nanoparticles, I.I. Shaganov, T.S. Perova, Kevin Berwick
Articles
An analysis of the effect of free and bound electrons on the optical properties of noble metals and their nanoparticles is performed, based on the Drude-Lorentz model. It is shown that the shifts in the absorption bands of plasmons localized in spherical nanoparticles with respect to the zero frequency of free electrons in a bulk metal can be estimated using the theory of resonant dipole-dipole interactions. The calculation includes account for differences between the effective and average electromagnetic fields. It is established that the difference in oscillator strength for free electrons in the bulk metal, obtained using the Drude-Lorentz model, …
Design And Investigation Of De Vries Liquid Crystals Based On 5-Phenyl-Pyrimidine And (R,R)-2,3-Epoxyhexoxy Backbone., S.P. Sreenilayam", D. Rodriguez-Lojo, V. P. Panov, V. Swaminathan, J. K. Vij, Yuri Panarin, E. Gorecka, A. Panov, P.J. Stevenson
Design And Investigation Of De Vries Liquid Crystals Based On 5-Phenyl-Pyrimidine And (R,R)-2,3-Epoxyhexoxy Backbone., S.P. Sreenilayam", D. Rodriguez-Lojo, V. P. Panov, V. Swaminathan, J. K. Vij, Yuri Panarin, E. Gorecka, A. Panov, P.J. Stevenson
Articles
Calamitic liquid crystals based on 5-phenyl-pyrimidine derivatives have been designed, synthesized, and characterized. The 5-phenyl pyrimidine core was functionalized with a chiral (R,R)-2,3-epoxyhexoxy chain on one side and either siloxane or perfluoro terminated chains on the opposite side. The one involving a perfluorinated chain shows SmA^{*} phase over a wide temperature range of 82 °C, whereas the siloxane analog exhibits both SmA^{*} and SmC^{*} phases over a broad range of temperatures, and a weak first-order SmA^{*}-SmC^{*} transition is observed. For the siloxane analog, the reduction factor for the layer shrinkage R (relative to its thickness at the SmA^{*}-SmC^{*} transition temperature, …
Aphonic: Adaptive Thresholding For Noise Cancellation In Smart Mobile Environments, Ruairí De Fréin
Aphonic: Adaptive Thresholding For Noise Cancellation In Smart Mobile Environments, Ruairí De Fréin
Articles
We propose a signal-channel, adaptive threshold selection technique for binary mask construction, namely APHONIC, (AdaPtive tHreshOlding for NoIse Cancellation) for smart mobile environments. Using this mask, we introduce two noise cancellation techniques that perform robustly in the presence of real-world interfering signals that are typically encountered by mobile users: a violin busker, a subway and busy city square sounds. We demonstrate that when the power of the time-frequency components of the voice of a mobile user does not significantly overlap with the components of the interference signal, the threshold learning and noise cancellation techniques significantly improve the Signal-to-Interference Ratio (SIR) …
Optimising The Performance Of Cement-Based Batteries, Aimee Byrne, Shane Barry, Niall Holmes Dr., Brian Norton
Optimising The Performance Of Cement-Based Batteries, Aimee Byrne, Shane Barry, Niall Holmes Dr., Brian Norton
Articles
The development of a battery using different cement-based electrolytes to provide a low but potentially sustainable source of electricity is described. The current, voltage, and lifespan of batteries produced using different electrolyte additives, copper plate cathodes, and (usually) aluminium plate anodes were compared to identify the optimum design, components, and proportions to increase power output and longevity. Parameters examined include water/cement ratio, anode to cathode surface area ratio, electrode material, electrode spacing, and the effect of sand, aggregate, salts, carbon black, silica fume, and sodium silicate on the electrolyte. The results indicate that the greatest and longest lasting power can …
Pattern Reconfigurable Back-To-Back Microstrip Patch Antenna, Kansheng Yang, Xiulong Bao, Patrick Mcevoy, Max Ammann
Pattern Reconfigurable Back-To-Back Microstrip Patch Antenna, Kansheng Yang, Xiulong Bao, Patrick Mcevoy, Max Ammann
Articles
A back-to- back microstrip patch antenna with a switchable pattern is proposed for WLAN applications. The patch elements, printed on FR-4 substrates with a common ground plane, are switched with a single-pole double-throw PIN diode circuit. Switching the feed selects either of two identical radiation patterns in the opposing hemispheres for spatial diversity that would benefit a distributed network.