9,204 research outputs found
An innovative EEG-based emotion recognition using a single channel-specific feature from the brain rhythm code method
IntroductionEfficiently recognizing emotions is a critical pursuit in brain–computer interface (BCI), as it has many applications for intelligent healthcare services. In this work, an innovative approach inspired by the genetic code in bioinformatics, which utilizes brain rhythm code features consisting of δ, θ, α, β, or γ, is proposed for electroencephalography (EEG)-based emotion recognition.MethodsThese features are first extracted from the sequencing technique. After evaluating them using four conventional machine learning classifiers, an optimal channel-specific feature that produces the highest accuracy in each emotional case is identified, so emotion recognition through minimal data is realized. By doing so, the complexity of emotion recognition can be significantly reduced, making it more achievable for practical hardware setups.ResultsThe best classification accuracies achieved for the DEAP and MAHNOB datasets range from 83–92%, and for the SEED dataset, it is 78%. The experimental results are impressive, considering the minimal data employed. Further investigation of the optimal features shows that their representative channels are primarily on the frontal region, and associated rhythmic characteristics are typical of multiple kinds. Additionally, individual differences are found, as the optimal feature varies with subjects.DiscussionCompared to previous studies, this work provides insights into designing portable devices, as only one electrode is appropriate to generate satisfactory performances. Consequently, it would advance the understanding of brain rhythms, which offers an innovative solution for classifying EEG signals in diverse BCI applications, including emotion recognition
Beam scanning by liquid-crystal biasing in a modified SIW structure
A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium
Exploring acceptance of autonomous vehicle policies using KeyBERT and SNA: Targeting engineering students
This study aims to explore user acceptance of Autonomous Vehicle (AV)
policies with improved text-mining methods. Recently, South Korean policymakers
have viewed Autonomous Driving Car (ADC) and Autonomous Driving Robot (ADR) as
next-generation means of transportation that will reduce the cost of
transporting passengers and goods. They support the construction of V2I and V2V
communication infrastructures for ADC and recognize that ADR is equivalent to
pedestrians to promote its deployment into sidewalks. To fill the gap where
end-user acceptance of these policies is not well considered, this study
applied two text-mining methods to the comments of graduate students in the
fields of Industrial, Mechanical, and Electronics-Electrical-Computer. One is
the Co-occurrence Network Analysis (CNA) based on TF-IWF and Dice coefficient,
and the other is the Contextual Semantic Network Analysis (C-SNA) based on both
KeyBERT, which extracts keywords that contextually represent the comments, and
double cosine similarity. The reason for comparing these approaches is to
balance interest not only in the implications for the AV policies but also in
the need to apply quality text mining to this research domain. Significantly,
the limitation of frequency-based text mining, which does not reflect textual
context, and the trade-off of adjusting thresholds in Semantic Network Analysis
(SNA) were considered. As the results of comparing the two approaches, the
C-SNA provided the information necessary to understand users' voices using
fewer nodes and features than the CNA. The users who pre-emptively understood
the AV policies based on their engineering literacy and the given texts
revealed potential risks of the AV accident policies. This study adds
suggestions to manage these risks to support the successful deployment of AVs
on public roads.Comment: 29 pages with 11 figure
Secure Routing Protocol To Mitigate Attacks By Using Blockchain Technology In Manet
MANET is a collection of mobile nodes that communicate through wireless
networks as they move from one point to another. MANET is an
infrastructure-less network with a changeable topology; as a result, it is very
susceptible to attacks. MANET attack prevention represents a serious
difficulty. Malicious network nodes are the source of network-based attacks. In
a MANET, attacks can take various forms, and each one alters the network's
operation in its unique way. In general, attacks can be separated into two
categories: those that target the data traffic on a network and those that
target the control traffic. This article explains the many sorts of assaults,
their impact on MANET, and the MANET-based defence measures that are currently
in place. The suggested SRA that employs blockchain technology (SRABC) protects
MANET from attacks and authenticates nodes. The secure routing algorithm (SRA)
proposed by blockchain technology safeguards control and data flow against
threats. This is achieved by generating a Hash Function for every transaction.
We will begin by discussing the security of the MANET. This article's second
section explores the role of blockchain in MANET security. In the third
section, the SRA is described in connection with blockchain. In the fourth
phase, PDR and Throughput are utilised to conduct an SRA review using
Blockchain employing PDR and Throughput. The results suggest that the proposed
technique enhances MANET security while concurrently decreasing delay. The
performance of the proposed technique is analysed and compared to the routing
protocols Q-AODV and DSR.Comment: https://aircconline.com/ijcnc/V15N2/15223cnc07.pd
Diseño y aplicaciones de sistemas de antenas inteligentes para redes inalámbricas en el contexto de la internet de las cosas
[SPA] Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. Las antenas de onda de fuga (LWA) consisten en una estructura de guÃa de onda que permite la fuga de parte de la potencia a lo largo de la estructura. Por esta razón, la radiación de la antena se produce por la fuga de energÃa. Para producir una radiación coherente, es necesario controlar esta tasa de radiación a lo largo de la estructura radiante. AsÃ, ajustando con precisión la tasa de radiación, se controla la forma del diagrama de radiación. Las LWAs han sido ampliamente estudiadas por la comunidad cientÃfica debido a sus ventajas, tales como, red de alimentación simple, alta directividad y escaneo en frecuencia pasivo. Sin embargo, presentan ciertas desventajas entre las cuales, la más importante a destacar es el efecto de beam-squinting. Éste se produce por la propiedad dispersiva inherente a este tipo de antenas. Además, presentan dificultades a la hora de generar radiación coherente en las direcciones broadside y endfire, aumentando la complejidad del diseÅ„o para la radiación en dichas direcciones. Las LWA han sido relativamente poco utilizadas en aplicaciones prácticas hasta la fecha, a pesar de sus ventajas. Las pocas aplicaciones en las que se han utilizado son los radares de onda continua modulada en frecuencia y los sistemas de enfoque controlado en frecuencia de campo cercano. Esta tesis propone el uso de las LWAs en aplicaciones prácticas aprovechando las ventajas mencionadas anteriormente y teniendo en cuenta los inconvenientes de este tipo de antenas para que su uso no sea limitado. Recientemente, las LWAs han sido propuestas para aplicaciones de localización de bajo coste, ya que permiten el diseÅ„o de estructuras planas con haces directivos. Además, debido al aumento exponencial del uso de la tecnologÃa, es necesario encontrar nuevas tecnologÃas para una transmisión de datos mayor, más rápida y más eficiente, manteniendo bajos costes de fabricación. Por lo tanto las LWAs pueden ser una solución crucial al mezclar bajos costes de fabricación, alta integrabilidad en diferentes sistemas debido a su tecnologÃa impresa planar y alta directividad al mismo tiempo que se aprovecha su caracterÃstica dispersiva que proporciona un escaneo pasivo en frecuencia. En este contexto, la principal aportación de esta Tesis consiste en el estudio, análisis, diseÅ„o e integración de LWAs en aplicaciones reales y prácticas. Esta Tesis presenta las siguientes tres contribuciones principales, definidas en los tres bloques principales de este documento: • Estudio y análisis de LWAs para su uso en sistemas de estimación de dirección de llegada basados en técnicas de amplitud de monopulso. Comparar las caracterÃsticas y prestaciones de las LWAs junto con las antenas comerciales más utilizadas. Para ello, diseÅ„ar y fabricar las HWM-LWAs con el fin de comparar sus prestaciones con las antenas de panel adquiridas comercialmente. Dado que cada aplicación requiere el diseÅ„o de una HWM-LWA nueva y diferente, estudiar y proponer una técnica eficiente de análisis y diseÅ„o de antenas para obtener fácilmente diagramas de radiación monopulso escaneados en frecuencia. • Una vez analizado que las HWM-LWA son una solución factible para su uso en aplicaciones reales de localización debido a sus diversas ventajas. Integrar las HWM-LWAs diseÅ„adas en sistemas digitales para estimación del ángulo de llegada en interiores. Por lo tanto, diseÅ„ar, desarrollar, configurar e integrar las LWAs en diferentes sistemas basados en las bandas de frecuencia Wi-Fi ISM de 2,4 GHz y 5 GHz. Finalmente, comparar los resultados de estimación obtenidos con otras soluciones propuestas para corroborar que los LWAs pueden ser utilizados en aplicaciones reales. • Asimismo, debido a su bajo coste de fabricación y a su principal propiedad de escaneo en frecuencia. Ampliar el uso de las LWAs para la localización angular en redes de sensores inalámbricas (WSN) utilizando la banda de frecuencias UHF de 900 MHz. Utilizando asà etiquetas RFID pasivas. También estudiar su aplicabilidad en WSNs utilizando etiquetas LoRa activas. Este documento se presenta como una Tesis por compendio, por lo que se presentarán y explicarán brevemente los 4 artÃculos de revistas que se han publicado durante el programa de doctorado. Además, también se presentarán algunos artÃculos de conferencias y otros trabajos en revisión para exponer algunas de las investigaciones que no han sido publicadas en revistas hasta la fecha de depósito de tesis. El documento está organizado como se indica a continuación: En la Introducción, se presenta una contextualización del estado del arte y una explicación rigurosa sobre las LWAs y las aplicaciones anteriormente mencionadas. Las dos partes siguientes se vi dedican a presentar y explicar brevemente los trabajos publicados que contribuyen a esta Tesis. En la parte II, se presentan los cuatro artÃculos que conforman el compendio. Esto es, el análisis de las LWAs para la estimación de la dirección del ángulo de llegada y la integración de las LWAs en sistemas de localización digital usando el protocolo Wi-Fi en el CapÃtulo 1, la banda de frecuencias ISM UHF 900 MHz se utiliza junto con los HWM-LWAs en el CapÃtulo 2, luego se implementa en un sistema en tiempo real para la estimación de la dirección de llegada de múltiples tags pasivos en el CapÃtulo 3 y la integración de LoRa en el CapÃtulo 4. Finalmente, en la Parte III, se discuten las conclusiones generales y las futuras lÃneas de investigación. [ENG] This doctoral dissertation has been presented in the form of thesis by publication. Leaky-Wave Antennas (LWA) consist on a waveguide structure which allows the leakage of part of the power along the structure. For this reason, the radiation of the antenna is produced by the leakage of power. In order to produce coherent radiation, it is necessary to control this leakage rate along the radiating structure. Thus, precisely adjusting the leakage rate, the shape of the radiation pattern is controlled. LWAs have been widely studied by the scientific community due to their advantages, such as, simple feeding network, high directivity and passive frequency-scanning performance. However, they present certain disadvantages among which, the most important to highlight is the beam-squinting effect. TThis is due to the inherent dispersion property of this type of antenna. In addition, LWAs present difficulties when generating coherent radiation in broadside and endfire directions, increasing the complexity of the design for radiation in these directions. LWAs have been relatively unused in practical applications to date, despite of their benefits. The few applications in which they have been used are frequency modulated continuous wave radars and near-field frequency controlled focusing systems.This thesis proposes the use of LWAs in practical applications by exploiting the advantages mentioned above while taking into account the drawbacks of this type of antennas so that their use is not limited. Recently, LWAs have been proposed for low-cost localization applications, as they allow the design of planar structures with directive beams. In addition, due to the exponential increase in the use of technology, it is necessary to find new technologies for higher, faster and more efficient data transmission while maintaining low manufacturing costs. Therefore, LWAs can be a crucial solution mixing low manufacturing costs, high integrability in different systems due to their planar printed technology and high directivity while taking advantage of their dispersive characteristic that provides passive frequency scanning. In this context, the main contribution of this Thesis consist of the study, analysis, design and integration of LWAs in real and practical applications. This Thesis presents the following three main contributions, defined in the three main blocks of this document: • Study and analysis of LWAs for its use in direction of arrival estimation systems based on monopulse amplitude techniques. Compare the characteristics and performance of LWAs along with widely used commercial antennas. For this purpose, design and manufacture the HWM-LWAs in order to compare their performance with commercially acquired panel antennas. Since each application requires the design of a new and different HWM-LWA, a main objective of this block is to study and propose an efficient antenna analysis and design technique to facilitate obtaining frequency-scanned monopulse patterns. • Once analyzed that LWAs are a feasible solution for its use in real localization applications due to their several advantages, integrate the designed half-width microstrip (HWM-LWAs) in digital indoor angle-of-arrival estimation systems. Therefore, design, develop, configure and integrate LWAs in different systems based on the Wi-Fi ISM 2.4 GHz and 5 GHz frequency bands. Finally, compare the obtained estimation results with other proposed solutions to corroborate that LWAs can be used in real applications. • Extending the use of antennas for angular localization in sensor networks using the 900 MHz UHF frequency band: the main properties of low manufacturing cost and passive frequency beam scanning can be used in other applications. Thus, the localization estimation of passive RFID tags is studied, as well as their application in Wireless Sensor Networks (WSNs) using active tags with LORA technology. This document is presented as a Thesis by compilation, so the 4 journal articles that have been published during the Ph.D program will be presented and briefly explained. Besides, some conference articles and other work under review will be also presented to expose some of the research that has not been published in journals. The document is organized as outlined hereafter: In Part I, a state-of-the-art contextualization, a rigorous explanation about LWAs and the previous applications mentioned above is presented. The next two parts are dedicated to present and briefly explain the published works included in this Thesis and their main contributions. In Part II the explanation of the four papers which compose the compendium are presented. This is, LWAs analysis for direction of arrival estimation and the integration of LWAs in digital Wi-Fi localization systems in chapter 1, the UHF 900 MHz ISM frequency band is used in conjunction with HWM-LWAs in chapter 2, then, it is implemented in a real time system for direction of arrival estimation of multi RFID tags in chapter 3 and LoRa integration in chapter 4. Finally, in Part III, the overall conclusions and the future research lines are discussed.Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. Está formada por un total de cuatro artÃculos. Article 1.-: A. Gil-Martinez, M. Poveda-Garcia, J. A. Lopez-Pastor, J. C. Sanchez-Aarnoutse and J. L. Gomez-Tornero, Wi-Fi Direction Finding with Frequency-Scanned Antenna and Channel Hopping Scheme IEEE sensors Journal, , vol. 22, no. 6, pp. 5210-5222, 2022. DOI: 10.1109/JSEN.2021.3122232. Article 2.-: A. Gil-Martinez, M. Poveda-Garcia, D. Cañete-Rebenaque, and J. L. Gomez-Tornero, Frequency-Scanned Monopulse Antenna for RSSI-based Direction Finding of UHF RFID tags IEEE Antennas and Wireless Propagation Letters,, vol. 21, no. 1, pp. 158-162, 2022. DOI: 10.1109/LAWP.2021.3122232. Article 3.-: A. Gil-Martinez, M. Poveda-Garcia, J. Garcia-Fernandez, M. Campo-Valera, D. Cañete-Rebenaque, and J. L. Gomez-Tornero, Direction Finding of RFID tags in UHF Band Using a Passive Beam-Scanning Leaky-Wave Antenna IEEE Journal of Radio Frequency Identi cation, doi: 10.1109/JRFID.2021.3122233. Article 4.-: J. L. Gomez-Tornero, A. Gil-Martinez, M. Poveda-Garcia and D. Cañete-Rebenaque, ARIEL: Passive Beam-Scanning Antenna TeRminal for Iridiscent and E cient LEO Satellite Connectivity in IEEE Antennas and Wireless Propagation Letters, doi: 10.1109/LAWP.2022.3193040.Escuela Internacional de Doctorado de la Universidad Politécnica de CartagenaUniversidad Politécnica de CartagenaPrograma Doctorado en TecnologÃas de la Información y las Comunicacione
Disk cutter drilling performance and optimization methods, rock strength correlation and field data analysis
Drilling a rock near the ground surface has an increasing demand for natural resources exploration, such as the recovery of minerals or crushed rock, the application of tunneling in civil engineering, etc. A recent field mine drilling at Baie Verte, located in the North of Newfoundland, Canada, involved a diamond drilling hole (DDH) for core recovery, which was intended for lithology analysis and as a pilot hole and a large diameter hole drilling (LDH) for ore excavation. This thesis includes an investigation of mining drilling on the LDH to determine abnormal drilling low rate of penetration (ROP) performance at a specific depth interval, where drilling data was analyzed based on each lithology. Also rock material characterization was conducted on granite rock to introduce a new method of Semi-Point Load Strength Index (Semi-PLSI) for estimation of the rock strength, and a detailed analysis of the effect of microwave irradiation on rock properties as one of the influencing technology of an increasing ROP. The above studies involve several laboratory tests, which include detailed rock core logging, mechanical tests, cutting size analysis, and mineral liberation analysis (MLA). The study of drilling performance at specific interval was influenced by high rock strength which was caused by a variation of rock micro-structure determined by MLA technology. Also, the rock characterization study of a new approach of Semi-PLSI shows excellent correlation and strength estimation with standard PLSI and other strength tests. Additionally, microwave irradiation (MI) analysis shows a decrease in strength, ultrasound wave velocities and elastic constants of the rock after the rocks are exposed to MI. Also, the effects of MI observed to increase drilling rate of penetration (D-ROP) of the rocks
The Metaverse: Survey, Trends, Novel Pipeline Ecosystem & Future Directions
The Metaverse offers a second world beyond reality, where boundaries are
non-existent, and possibilities are endless through engagement and immersive
experiences using the virtual reality (VR) technology. Many disciplines can
benefit from the advancement of the Metaverse when accurately developed,
including the fields of technology, gaming, education, art, and culture.
Nevertheless, developing the Metaverse environment to its full potential is an
ambiguous task that needs proper guidance and directions. Existing surveys on
the Metaverse focus only on a specific aspect and discipline of the Metaverse
and lack a holistic view of the entire process. To this end, a more holistic,
multi-disciplinary, in-depth, and academic and industry-oriented review is
required to provide a thorough study of the Metaverse development pipeline. To
address these issues, we present in this survey a novel multi-layered pipeline
ecosystem composed of (1) the Metaverse computing, networking, communications
and hardware infrastructure, (2) environment digitization, and (3) user
interactions. For every layer, we discuss the components that detail the steps
of its development. Also, for each of these components, we examine the impact
of a set of enabling technologies and empowering domains (e.g., Artificial
Intelligence, Security & Privacy, Blockchain, Business, Ethics, and Social) on
its advancement. In addition, we explain the importance of these technologies
to support decentralization, interoperability, user experiences, interactions,
and monetization. Our presented study highlights the existing challenges for
each component, followed by research directions and potential solutions. To the
best of our knowledge, this survey is the most comprehensive and allows users,
scholars, and entrepreneurs to get an in-depth understanding of the Metaverse
ecosystem to find their opportunities and potentials for contribution
Acoustic modelling, data augmentation and feature extraction for in-pipe machine learning applications
Gathering measurements from infrastructure, private premises, and harsh environments can be difficult and expensive. From this perspective, the development of
new machine learning algorithms is strongly affected by the availability of training
and test data. We focus on audio archives for in-pipe events. Although several
examples of pipe-related applications can be found in the literature, datasets of
audio/vibration recordings are much scarcer, and the only references found relate
to leakage detection and characterisation. Therefore, this work proposes a methodology to relieve the burden of data collection for acoustic events in deployed pipes.
The aim is to maximise the yield of small sets of real recordings and demonstrate
how to extract effective features for machine learning. The methodology developed
requires the preliminary creation of a soundbank of audio samples gathered with
simple weak annotations. For practical reasons, the case study is given by a range
of appliances, fittings, and fixtures connected to pipes in domestic environments.
The source recordings are low-reverberated audio signals enhanced through a
bespoke spectral filter and containing the desired audio fingerprints. The soundbank is then processed to create an arbitrary number of synthetic augmented
observations. The data augmentation improves the quality and the quantity of
the metadata and automatically creates strong and accurate annotations that
are both machine and human-readable. Besides, the implemented processing
chain allows precise control of properties such as signal-to-noise ratio, duration
of the events, and the number of overlapping events. The inter-class variability
is expanded by recombining source audio blocks and adding simulated artificial
reverberation obtained through an acoustic model developed for the purpose.
Finally, the dataset is synthesised to guarantee separability and balance. A few
signal representations are optimised to maximise the classification performance,
and the results are reported as a benchmark for future developments. The contribution to the existing knowledge concerns several aspects of the processing chain
implemented. A novel quasi-analytic acoustic model is introduced to simulate
in-pipe reverberations, adopting a three-layer architecture particularly convenient
for batch processing. The first layer includes two algorithms: one for the numerical
calculation of the axial wavenumbers and one for the separation of the modes. The
latter, in particular, provides a workaround for a problem not explicitly treated in the
literature and related to the modal non-orthogonality given by the solid-liquid interface in the analysed domain. A set of results for different waveguides is reported
to compare the dispersive behaviour against different mechanical configurations.
Two more novel solutions are also included in the second layer of the model and
concern the integration of the acoustic sources. Specifically, the amplitudes of the
non-orthogonal modal potentials are obtained using either a distance minimisation
objective function or by solving an analytical decoupling problem. In both cases,
results show that sources sufficiently smooth can be approximated with a limited
number of modes keeping the error below 1%. The last layer proposes a bespoke
approach for the integration of the acoustic model into the synthesiser as a reverberation simulator. Additional elements of novelty relate to the other blocks of the
audio synthesiser. The statistical spectral filter, for instance, is a batch-processing
solution for the attenuation of the background noise of the source recordings. The
signal-to-noise ratio analysis for both moderate and high noise levels indicates
a clear improvement of several decibels against the closest filter example in the
literature. The recombination of the audio blocks and the system of fully tracked
annotations are also novel extensions of similar approaches recently adopted in
other contexts. Moreover, a bespoke synthesis strategy is proposed to guarantee
separable and balanced datasets. The last contribution concerns the extraction
of convenient sets of audio features. Elements of novelty are introduced for the
optimisation of the filter banks of the mel-frequency cepstral coefficients and the
scattering wavelet transform. In particular, compared to the respective standard
definitions, the average F-score performance of the optimised features is roughly
6% higher in the first case and 2.5% higher for the latter. Finally, the soundbank,
the synthetic dataset, and the fundamental blocks of the software library developed
are publicly available for further research
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