Engineering Commons^™

Coordinate Transformation-Free Observer-Based Adaptive Estimation Of Distorted Single-Phase Grid Voltage Signal, Hafiz Ahmed, Mominul Ahsan, Mohamed Benbouzid, Alhussein Albarbar, Mohammad Shahjalal, Samet Biricik

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This paper studies the phase and frequency estimation problem of single-phase grid voltagesignal in the presence of DC offset and harmonics. For this purpose, a novel parameterized linear modelof the grid voltage signal is considered where the unknown frequency of the grid is considered as theparameter. Based on the developed model, a linear observer (Luenberger type) is proposed. Then usingLyapunov stability theory, an estimator of the unknown grid frequency is developed. In order to deal with thegrid harmonics, multiple parallel observers are then proposed. The proposed technique is inspired by otherLuenberger observers already proposed in the literature. Those techniques use …

The Viability Of Organic Dyes In Luminescent Down-Shifting Layers For The Enhancement Of Si Solar Cell Efficiency, Aaron Glenn, Conor Mcloughlin, Hind Ahmed, Hoda Akbari, Subhash Chandra, Sarah Mccormack

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The main energy losses in solar cells are related to spectral losses where high energy photons are not used efficiently, and energy is lost via thermalization which reduces the solar cell’s overall efficiency. A way to tackle this is to introduce a luminescent down-shifting layer (LDS) to convert these high energy photons into a lower energy bracket helping the solar cell to absorb them and thus generating a greater power output. In this paper, lumogen dye Violet 570 has been used as LDS coated films of 10μm and 60μm placed on top of Si solar cells. The dye was incorporated …

Evaluating Compressive Properties And Morphology Of Expandable Polyurethane Foam For Use In A Synthetic Paediatric Spine, Nor Amalina Muhayudin, Khairul Salleh Basaruddin, Fiona Mcevoy, Anthony Tansey

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An expandable rigid PU foam can turns into complex shapes, with a shell like structure onthe outside and honeycomb structure on the inside, which can be easily shaped to a vertebraform. The present study aims to determine whether expandable rigid polyurethane foamwas an appropriate substitute for rigid block polyurethane foam to model the trabecularbone. Static compression tests were performed to determine compressive moduli and yieldstresses on three polyurethane foam densities namely 0.16 g/cm3, 0.24 g/cm3and 0.42 g/cm3.Morphology of the PU foams for all densities was also observed. The compressive modulusfor 0.16 g/cm3and 0.24 g/cm3were found varied from 40 to 43 …

Low-Pass Filtering Or Gain Tuning Free Simple Dc Offset Rejection Technique For Single And Three-Phase Systems, Samet Biricik, Hafiz Ahmed, Mohamed Benbouzid

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This paper aims to address the DC offset rejection problem in grid synchronization algorithm. A simple approach to estimate the unknown grid frequency in the presence of DC offset is proposed for this purpose. Some of the existing techniques available in the literature use either low-pass filter or an additional integrator to eliminate the DC offset. Both approaches require an additional parameter to tune. However, tuning the additional parameter is not straightforward. Moreover, tuning the overall system can be complicated due to the presence of DC offset rejection part. The proposed approach does not require any additional parameter to tune. …

Enhanced Gas Barrier Properties Of Graphene Oxide/Rubber Composites With Strong Interfaces Constructed By Graphene Oxide And Sulfur, Long Zheng, Stephen Jerrams, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

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Constructing strong interfacial interactions and complex filler networks is crucial to establishing high gas barrier properties in rubber composites. In this research, sulfur-graphene oxide (S-GO) hybrids were prepared by in situ growth of sulfur on the surfaces of GO sheets. The S-GO hybrids were also introduced into butadiene styrene rubber (SBR) using a green method of latex compounding. Results showed that sulfur could melt and spread on the surface of the GO during the crosslinking process at high temperatures. This process prevented the aggregation of GO and resulted in a fine dispersion of GO and complex filler networks in S-GO/SBR …

Enhanced Covalent Interface, Crosslinked Network And Gas Barrier Property Of Functionalized Graphene Oxide/Styrene-Butadiene Rubber Composites Triggered By Thiol-Ene Click Reaction, Long Zheng, Stephen Jerrams, Tian Su, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

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The high gas barrier property of a rubber composite is of great significance for reducing the exhaust gas emissions due to tire rolling resistance and hence the contribution this factor makes to environmental protection. Enhanced covalent interfaces and crosslinked networks are crucial to the gas barrier property of rubber composites. In this research, γ-mercaptopropyltriethoxysilane (MPS) modified GO (MGO)/styrene-butadiene rubber (SBR) composites were prepared by a synergetic strategy of latex compounding method and thiol-ene click reaction. It was found that the mercapto groups in MGO reacted with the vinyl groups in SBR molecules through thiol-ene click reaction during the crosslinking process …

An Examination Of The Role Of Spatial Ability In The Process Of Problem Solving In Chemical Engineering, Sheryl Sorby, Gavin Duffy, Norman Loney

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Engineers often communicate with one another through drawings or sketches and understanding technical information through graphical representations is a skill necessary for engineering practice. Well-developed spatial skills are known to be important to understanding technical drawings and are therefore, important to success in engineering. Unfortunately, of all cognitive processes, spatial skills show robust gender differences, favouring males, which could contribute to the underrepresentation of women in engineering. In this research, we administered a test of spatial cognition to students enrolled in a common 3rd year course in chemical engineering . In a second session, students were given a set of …

Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang

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A low-cost optical fibre sensor based on two cascaded balloon-like bent fibre (BBF) structures for simultaneous displacement and temperature measurement is reported. The sensor is fabricated by cascading two balloon-like bent single-mode fibres (SMFs) which with different bending radii, generating two separate interference dips within a limited wavelength range. The wavelength of the two interference dips exhibits different responses to external displacement and temperature variations, hence simultaneous measurement of displacement and temperature is realized. Experimental results show that the proposed optical fibre sensor achieves a displacement sensitivity of −318.8 pm/μm and a temperature sensitivity of 47.4 pm/°C. Taking advantage of …

Saperi: Approaching Gender Gap Using Spatial Ability Training Week In High-School Context, Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, Anita Tabacco

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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

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

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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 …

Investigation On The Polarization Dependence Of An Angled Polished Multimode Fibre Structure, Ruoning Wang, Ke Tian, Meng Zhang, Yuxuan Jiang, Libo Yuan, Guoyong Jin, Gerald Farrell, Elfed Lewis, Pengfei Wang

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An angled polished multimode (APM) fibre structure is described for the first time, to the best our knowledge, and its polarization dependence is investigated theoretically and experimentally. Two angled planes are established in the multimode fibre (MMF) section of a single-mode-multimode-single-mode (SMS) fibre structure using the fibre side-polishing technique, forming the APM fibre structure. This designed circular asymmetric geometry induces different propagation characteristics for the TE and TM modes within the MMF. Simulated and experimental results both show that this difference is enhanced as the polishing angle increases, and a maximum extinction ratio (ER) of the spectrum of 13 dB …

Daylight: What Makes The Difference?, M. Knoop, O. Stefani, B. Bueno, B. Matusiak, R. Hobday, A. Wirz-Justice, K. Martiny, T. Tandermann, N. Zemmouri, S. Appelt, Brian Norton

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Light is necessary for vision; it enables us to sense and perceive our surroundings and in many direct and indirect ways, via eye and skin, affects our physiological and psychological health. The use of light in built environments has comfort, behavioural, economic and environmental consequences. Daylight has many particular benefits including excellent visual performance, permitting good eyesight, effective entrainment of the circadian systemas well as a number of acute non-image forming effects and the important role of vitamin D production. Some human responses to daylight seem to be well defined whilst others require more research to be adequately understood. This …

Comparison Of Hybridizing Options For Solar Heat, Biomass And Heat Storage For Electricity Generation In Spain, Cm Iftekhar Hussain, Brian Norton, Aidan Duffy

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Diurnal and seasonal variations of direct solar energy circumscribe locations suitable for sole use of concentrated solar power for electricity generation, whereas to generate electricity at night and during winter months, biomass systems can be used that incur fuel expenditures and may encounter fuel supply discontinuities. Combining solar heat, biomass conversion and heat storage in a hybrid electricity generation plant may overcome the limitations of sole use of any one of these energy sources in specific geographic and/or economic conditions. In this work standalone biomass, hybrid concentrated solar power-biomass and hybrid concentrated solar power-biomass-thermal energy storage power generation systems 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

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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 …

Sustainable And Resilient Construction: Current Status And Future Challenges, Niamh Murtagh, Lloyd Scott, Jingli Fan

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The construction industry globally is one of the most environmentally damaging of sectors. Additionally, the resources consumed and the operational energy requirements of buildings are ‘locked-in’, potentially for decades. The Intergovernmental Panel on Climate Change has recognised construction as a sector in which significant improvements can, and indeed must, be made. But the industry is often argued to be unique, in its multiplicity of stakeholders, transient organisational structures, avoidance of risk and impact on society. The current Virtual Special Issue (VSI) sought to bring together a collection of papers on progress and potential for improvement in the construction sector, in …

Thermal Analysis And Post Construction Verification, Cormac Flood, Lloyd Scott

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Purpose – The residential sector in Ireland accounted for 25 per cent of energy related CO2 emissions in 2016 through burning fossil fuels, a major contributor to climate change. In support of Ireland’s CO2 reduction targets, the existing housing stock could contribute greatly to the reduction of space-heating energy demand through retrofit. Approximately 50 per cent of Ireland’s 2m dwellings pre-date building regulations and are predominantly of cavity and solid wall construction, the performance of which has not been extensively investigated at present. Although commitment to thermal upgrade/retrofit of existing buildings may increase under future government policies, the poor characterisation …

Mapping The In-Plane Electric Field Inside Irradiated Diodes, L. Poley, A.J. Blue, C. Buttar, V. Cindro, C. Darroch, V. Fadayev, J. Fernandez-Tejero, C. Fleta, C. Helling, C. Labitan, I. Mandic, S.N. Santpur, D. Sperlich, M. Ullan, Y. Unno

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A significant aspect of the Phase-II Upgrade of the ATLAS detector is the replacement of the current Inner Detector with the ATLAS Inner Tracker (ITk). The ATLAS ITk is an all-silicon detector consisting of a pixel tracker and a strip tracker. Sensors for the ITk strip tracker have been developed to withstand the high radiation environment in the ATLAS detector after the High Luminosity Upgrade of the Large Hadron Collider at CERN, which will significantly increase the rate of particle collisions and resulting particle tracks. During their operation in the ATLAS detector, sensors for the ITk strip tracker are expected …

Indirect Sliding Mode Control For Dc-Dc Sepic Converters, Hasan Komurcugil, Samet Biricik, Naki Guler

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This article presents an indirect sliding mode control (SMC) for single-ended primary-inductor converters (SEPIC). Unlike the conventional SMC methods, the proposed SMC method employs a sliding surface function based on the input current error only. The use of such sliding surface function not only simplifies the implementation but also reduces the cost of implementation. It is shown that the output voltage control can be achieved indirectly. The input current reference is generated by a proportional-integral (PI) regulator. The existence condition and the region of the closed-loop system are determined for all possibilities of the PI gains. The performance of the …

A Closed-Loop Renewable Energy Evaluation Framework, Tony Kealy

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Many businesses that have embraced renewable energy projects as part of their corporate sustainability efforts lack direction concerning how the projects are assessed. This study presents a framework that prescribes the necessary stages that allow a robust project evaluation to take place. The framework should assist practitioners in ascertaining if renewable energy projects, such as wind turbines and hydroelectric generators, contribute to energy cost savings and a reduction in CO2 emissions. The conceptual framework was developed using empirical data accessed from an 850-kW wind turbine case study and a 40-kW hydro-electric case study and embraced the action research methodology. Both …

Ambiqual: Towards A Quality Metric For Headphone Rendered Compressed Ambisonic Spatial Audio, Miroslaw Narbutt, Jan Skoglund, Andrew Allen, Michael Chinen, Dan Barry, Andrew Hines

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Spatial audio is essential for creating a sense of immersion in virtual environments. Efficient encoding methods are required to deliver spatial audio over networks without compromising Quality of Service (QoS). Streaming service providers such as YouTube typically transcode content into various bit rates and need a perceptually relevant audio quality metric to monitor users’ perceived quality and spatial localization accuracy. The aim of the paper is two-fold. First, it is to investigate the effect of Opus codec compression on the quality of spatial audio as perceived by listeners using subjective listening tests. Secondly, it is to introduce AMBIQUAL, a full …

Tracing Sources Of Natural Organic Matter, Trihalomethanes And Metals In Groundwater From A Karst Region, Connie O'Driscoll, Eoin Mcgillicuddy, Peter Croot, Pamela Bartley, John Mcmyler, Jerome Sheahan, Liam Morrison

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Groundwater offers an important source for drinking water around the world; however, groundwater quality is under increasing pressure and is particularly vulnerable in karst areas. Total organic carbon (TOC) is significantly related to groundwater quality and when not removed by water treatment processes can give rise to the formation of disinfection by-products trihalomethanes (THMs) above the level of compliance. This study investigated the source of organic matter giving rise to the THM exceedances in a groundwater supply in a karst area. Results highlighted that source water for this groundwater supply was prone to surface water infiltration linked to rainfall events; …

Classification And Biological Identity Of Complex Nano Shapes, Luca Boselli, Hender Lopez, Wei Zhang, Qi Cai, Valeria A. Giannone, Jingji Li, Alirio Moura, João M. De Araujo, Jennifer Cookman, Valentina Castagnola, Yan Yan, Kenneth A. Dawson

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Everywhere in our surroundings we increasingly come in contact with nanostructures that have distinctive complex shape features on a scale comparable to the particle itself. Such shape ensembles can be made by modern nano-synthetic methods and many industrial processes. With the ever growing universe of nanoscale shapes, names such as “nanoflowers” and “nanostars” no longer precisely describe or characterise the distinct nature of the particles. Here we capture and digitise particle shape information on the relevant size scale and create a condensed representation in which the essential shape features can be captured, recognized and correlated. We find the natural emergence …

Confinement Of Monolithic Stationary Phases In Targeted Regions Of 3d-Printed Titanium Devices Using Thermal Polymerization, Marta Passamonti, Ischa L. Bremer, Suhas H. Nawada, Sinead A. Currivan, Andrea F.G. Gargano, Peter J. Schoenmakers

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Abstract

In this study, we have prepared thermally initiated polymeric monolithic stationary phases within discrete regions of 3D-printed titanium devices. The devices were created with controllable hot and cold regions. The monolithic stationary phases were first locally created in capillaries inserted into the channels of the titanium devices. The homogeneity of the monolith structure and the interface length were studied by scanning a capacitively coupled conductivity contactless detector (C4D) along the length of the capillary. Homogeneous monolithic structures could be obtained within a titanium device equipped with a hot and cold jacket connected to two water baths. The confinement method …

Microfluidic Flow Direction And Rate Vector Sensor Based On A Partially Gold-Coated Tfbg, Changyu Shen, Dejun Liu, Xiaokang Lian, Tingting Lang, Chunliu Zhao, Yuliya Semenova, Jacques Albert

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In microfluidic chips applications, the monitoring of the rate and the direction of a microfluidic flow is very important. Here, we demonstrate a liquid flow rate and a direction sensor using a partially gold-coated tilted fiber Bragg grating (TFBG) as the sensing element. Wavelength shifts and amplitude changes of the TFBG transmission resonances in the near infrared reveal the direction of the liquid flowing along the fiber axis in the vicinity of the TFBG due to a nanoscale gold layer over part of the TFBG. For a device length of 10 mm (and a diameter of 125 µm for easy …

In Situ Image Processing And Data Binning Strategy For Particle Engineering Applications, Toufic El Arnaout, Patrick J. Cullen

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Crystallization control can be improved through real-time monitoring technologies. Here, a workflow is demonstrated on rapid batch cooling crystallization of L-glutamic acid. First, in situ images were generated using video microscopy sensors and analyzed, by employing a single, rapid macro code to extract particle data descriptors. A binning procedure (over time) was performed, where every data point represented the counts of particles within a specific size or shape range per 100 images. This binning method was found more informative in tracking of the populations compared to whole image averages or individual particle datapoints. This study provides a step-by-step guide towards …

Cognitive Performance In Midlife Type 2 Diabetes: Results Form The Enbind Study, A. H. Dyer, L. Mckenna, G. Gamage, N. M. Bourke, Isabelle Killane, M. Widdowson, C. P. Woods, J. Gibney, R. Reilly, D. O'Neill, S. P. Kennelly

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Aims: To establish the impact of uncomplicated type 2 diabetes on cognitive and neuropsychological performance in midlife. Methods: We performed a cross-sectional study of middle-aged adults with uncomplicated type 2 diabetes and a cohort of healthy control participants. General cognition was assessed using the Montreal Cognitive Assessment test and neuropsychological assessment was undertaken using a detailed neuropsychological assessment battery. Results: A total of 152 participants (102 with type 2 diabetes and 50 controls) were recruited (mean age 52 ± 8 years, 51% women). Participants with midlife type 2 diabetes were more than twice as likely to make an error on …

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

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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.

Performance Investigation Of Peak Shrinking And Interpolating The Papr Reduction Technique For Lte-Advance And 5g Signals, Somayeh Mohammady, Ronan Farrell, David Malone, John Dooley

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Orthogonal frequency division multiplexing (OFDM) has become an indispensable part of waveform generation in wideband digital communication since its first appearance in digital audio broadcasting (DAB) in Europe in 1980s, and it is indeed in use. As has been seen, the OFDM based waveforms work well with time division duplex operation in new radio (NR) systems in 5G systems, supporting delay-sensitive applications, high spectral efficiency, massive multiple input multiple output (MIMO) compatibility, and ever-larger bandwidth signals, which has demonstrated successful commercial implementation for 5G downlinks and uplinks up to 256-QAM modulation schemes. However, the OFDM waveforms suffer from high peak …

Self-Similar Pcosecond Pulse Compression For Supercontinuum Generation At Mid-Infrared Wavelength In Silicon Strip Waveguides, Yujun Cheng, Jinhui Yuan, Chao Mei, Feng Li, Zhe Kang, Binbin Yan, Xian Zhou, Qiang Wu, Kuiru Wang, Xinzhu Sang, Keping Long, Chongxiu Yu, Gerald Farrell

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Self-similar pulse compression has important application in highly coherent supercontinuum (SC) generation. In this paper, we numerically present the mid-infrared self-similar picosecond pulse compression in a tapered suspended silicon strip waveguide, which is designed with exponentially decreasing dispersion profile along the direction of propagation. When the variation of the Kerr nonlinear coefficient ��(z), linear and nonlinear losses, higher-order nonlinearity, and higher-order dispersion are taken into consideration, the simulation result shows that a 1 ps input pulse centered at wavelength 2.8 μm could be self-similarly compressed to 47.06 fs in a 3.9-cm waveguide taper, along with a compression factor ��c of …

Applications Of Artificial Intelligence To Cryptography, Jonathan Blackledge, Napo Mosola

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This paper considers some recent advances in the field of Cryptography using Artificial Intelligence (AI). It specifically considers the applications of Machine Learning (ML) and Evolutionary Computing (EC) to analyze and encrypt data. A short overview is given on Artificial Neural Networks (ANNs) and the principles of Deep Learning using Deep ANNs. In this context, the paper considers: (i) the implementation of EC and ANNs for generating unique and unclonable ciphers; (ii) ML strategies for detecting the genuine randomness (or otherwise) of finite binary strings for applications in Cryptanalysis. The aim of the paper is to provide an overview on …