4,384 research outputs found

    Beam scanning by liquid-crystal biasing in a modified SIW structure

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    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

    Keterlibatan Stakeholder Pada Strategi TI; Studi Pemetaan Sistematis

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    Mempelajari stakeholder bertujuan untuk menjelaskan bagaimana perusahaan memperlakukan stakeholder mereka dan dampak pilihan yang dibuat terhadap kinerja perusahaan secara keseluruhan. Mempelajari strategi stakeholder telah dilakukan pada berbagai bidang.  Namun, penelitian sebelumnya kebanyakan pada bidang industri dan management, hanya ada sedikit literatur yang membahas menyeluruh analisis stakeholder pada teknologi informasi utamanya pada strategi TI. Padahal pada teknologi informasi (TI), manfaat keterlibatan stakeholders digunakan sebagai dasar konseptual untuk mengembangkan rencana teknologi. Berdasarkan keadaan yang ada, tujuan dari paper ini adalah untuk membuat peta sistematis berdasarkan literatur dari lima tahun terakhir yaitu periode 2017-2021. Review literatur yang digunakan berasal dari database jurnal internasional yaitu Emerald, Elsevier, Tandfonline, dan springer dengan pencarian berdasarkan tahun, bidang, dan jenis literatur yang digunakan yaitu jurnal. Berdasarkan hasil pencarian, selanjutnya diseleksi jurnal yang berfokus dapat menjawab pertanyaan penelitian. Adapun Pertanyaan penelitian yang digunakan adalah menjawab peran keterlibatan stakeholder dalam strategi teknologi informasi dan implementasi stakeholder pada masing-masing area TI. Selain menjawab pertanyaan penelitian paper ini juga melakukan klasifikasi literatur yang didapat menurut fokus yang berbeda, yaitu demografi jurnal penelitian dan jenis stakeholder yang digunakan. Hasil dari paper ini diharapkan dapat berkontribusi dalam merumuskan peran stakeholder dalam strategi TI dan mengidentifikasi faktor implementasi yang harus diperhatikan dalam strategi TI. AbstractStudying stakeholders aims to explain how companies treat their stakeholders and the impact of their choices on the company's overall performance. Learning stakeholder strategies has been carried out in various fields. However, previous research has primarily been in the areas of industry and management; there is little literature that discusses a thorough stakeholder analysis on information technology, especially in IT strategy. Whereas in information technology (IT), the benefits of stakeholder involvement are used as a conceptual basis for developing technology plans. Based on the existing circumstances, this paper aims to create a systematic map based on the literature from the last five years, namely the period 2017-2021. The literature review comes from a database of international journals, namely Emerald, Elsevier, Tandfonline, and Springer by searching by year, field, and type of literature used. The search results then selected journals that focus on answering research questions. The research question used is to answer the role of stakeholder involvement in information technology strategy and stakeholder implementation in each IT area. In addition to answering research questions, this paper also classifies the literature obtained according to different focuses, namely the demographics of research journals and the types of stakeholders used. The results of this paper are expected to contribute to formulating the role of stakeholders in IT strategy and identify implementation factors that must be considered in IT strategy

    Distributed Spatial Data Sharing: a new era in sharing spatial data

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    The advancements in information and communications technology, including the widespread adoption of GPS-based sensors, improvements in computational data processing, and satellite imagery, have resulted in new data sources, stakeholders, and methods of producing, using, and sharing spatial data. Daily, vast amounts of data are produced by individuals interacting with digital content and through automated and semi-automated sensors deployed across the environment. A growing portion of this information contains geographic information directly or indirectly embedded within it. The widespread use of automated smart sensors and an increased variety of georeferenced media resulted in new individual data collectors. This raises a new set of social concerns around individual geopricacy and data ownership. These changes require new approaches to managing, sharing, and processing geographic data. With the appearance of distributed data-sharing technologies, some of these challenges may be addressed. This can be achieved by moving from centralized control and ownership of the data to a more distributed system. In such a system, the individuals are responsible for gathering and controlling access and storing data. Stepping into the new area of distributed spatial data sharing needs preparations, including developing tools and algorithms to work with spatial data in this new environment efficiently. Peer-to-peer (P2P) networks have become very popular for storing and sharing information in a decentralized approach. However, these networks lack the methods to process spatio-temporal queries. During the first chapter of this research, we propose a new spatio-temporal multi-level tree structure, Distributed Spatio-Temporal Tree (DSTree), which aims to address this problem. DSTree is capable of performing a range of spatio-temporal queries. We also propose a framework that uses blockchain to share a DSTree on the distributed network, and each user can replicate, query, or update it. Next, we proposed a dynamic k-anonymity algorithm to address geoprivacy concerns in distributed platforms. Individual dynamic control of geoprivacy is one of the primary purposes of the proposed framework introduced in this research. Sharing data within and between organizations can be enhanced by greater trust and transparency offered by distributed or decentralized technologies. Rather than depending on a central authority to manage geographic data, a decentralized framework would provide a fine-grained and transparent sharing capability. Users can also control the precision of shared spatial data with others. They are not limited to third-party algorithms to decide their privacy level and are also not limited to the binary levels of location sharing. As mentioned earlier, individuals and communities can benefit from distributed spatial data sharing. During the last chapter of this work, we develop an image-sharing platform, aka harvester safety application, for the Kakisa indigenous community in northern Canada. During this project, we investigate the potential of using a Distributed Spatial Data sharing (DSDS) infrastructure for small-scale data-sharing needs in indigenous communities. We explored the potential use case and challenges and proposed a DSDS architecture to allow users in small communities to share and query their data using DSDS. Looking at the current availability of distributed tools, the sustainable development of such applications needs accessible technology. We need easy-to-use tools to use distributed technologies on community-scale SDS. In conclusion, distributed technology is in its early stages and requires easy-to-use tools/methods and algorithms to handle, share and query geographic information. Once developed, it will be possible to contrast DSDS against other data systems and thereby evaluate the practical benefit of such systems. A distributed data-sharing platform needs a standard framework to share data between different entities. Just like the first decades of the appearance of the web, these tools need regulations and standards. Such can benefit individuals and small communities in the current chaotic spatial data-sharing environment controlled by the central bodies

    Corporate Social Responsibility: the institutionalization of ESG

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    Understanding the impact of Corporate Social Responsibility (CSR) on firm performance as it relates to industries reliant on technological innovation is a complex and perpetually evolving challenge. To thoroughly investigate this topic, this dissertation will adopt an economics-based structure to address three primary hypotheses. This structure allows for each hypothesis to essentially be a standalone empirical paper, unified by an overall analysis of the nature of impact that ESG has on firm performance. The first hypothesis explores the evolution of CSR to the modern quantified iteration of ESG has led to the institutionalization and standardization of the CSR concept. The second hypothesis fills gaps in existing literature testing the relationship between firm performance and ESG by finding that the relationship is significantly positive in long-term, strategic metrics (ROA and ROIC) and that there is no correlation in short-term metrics (ROE and ROS). Finally, the third hypothesis states that if a firm has a long-term strategic ESG plan, as proxied by the publication of CSR reports, then it is more resilience to damage from controversies. This is supported by the finding that pro-ESG firms consistently fared better than their counterparts in both financial and ESG performance, even in the event of a controversy. However, firms with consistent reporting are also held to a higher standard than their nonreporting peers, suggesting a higher risk and higher reward dynamic. These findings support the theory of good management, in that long-term strategic planning is both immediately economically beneficial and serves as a means of risk management and social impact mitigation. Overall, this contributes to the literature by fillings gaps in the nature of impact that ESG has on firm performance, particularly from a management perspective

    Development of ultra high-performance fiber reinforced concrete barge for 5 MW wind turbine

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    Floating wind turbines are gaining more popularity today as one of the effective green energy harvesting systems. In the effort to reduce the cost of construction for floating wind turbines, concrete support structures and concrete barge have been developed. However, due to the concrete low tensile strength and susceptibility to chemical action and freezing temperatures, the concrete barges are designed with very large sections resulting in high energy consumption, high volume of construction materials, weightier structure and more heavy equipment for fabrication and installation. Therefore, in order to overcome these challenges, in this study Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) is proposed for use in casting a barge for a floating offshore wind turbine and compared to a reinforced cement concrete (RCC) barge. The experimental tests conducted on the UHPFRC and RCC barge small sized prototypes, showed less heel on the RCC barge compared to the UHPFRC barge. However, the RCC barge experienced severe green water load which could cause it to capsize. The hydrodynamic analysis results from the finite element analysis showed less pitch motions in the UHPFRC barge in 7 out of the 12 DLCs considered. The roll motions were less than 50 in both barges with insignificant difference between them, while in heave motions, the UHPFRC barge experienced 10% to 20% less motions than the RCC barge in all 12 DLCs. In the structural analysis, the maximum deformation of the UHPFRC barge was 14 mm, which is 129% higher than the deformation of the RCC barge. In overall, the UHPFRC barge proved to be more effective in achieving better hydrodynamic motions for the barge floater in comparison to the RCC barge and can be considered as alternative to the conventional reinforced cement concrete material

    Self-Healing in Cyber–Physical Systems Using Machine Learning:A Critical Analysis of Theories and Tools

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    The rapid advancement of networking, computing, sensing, and control systems has introduced a wide range of cyber threats, including those from new devices deployed during the development of scenarios. With recent advancements in automobiles, medical devices, smart industrial systems, and other technologies, system failures resulting from external attacks or internal process malfunctions are increasingly common. Restoring the system’s stable state requires autonomous intervention through the self-healing process to maintain service quality. This paper, therefore, aims to analyse state of the art and identify where self-healing using machine learning can be applied to cyber–physical systems to enhance security and prevent failures within the system. The paper describes three key components of self-healing functionality in computer systems: anomaly detection, fault alert, and fault auto-remediation. The significance of these components is that self-healing functionality cannot be practical without considering all three. Understanding the self-healing theories that form the guiding principles for implementing these functionalities with real-life implications is crucial. There are strong indications that self-healing functionality in the cyber–physical system is an emerging area of research that holds great promise for the future of computing technology. It has the potential to provide seamless self-organising and self-restoration functionality to cyber–physical systems, leading to increased security of systems and improved user experience. For instance, a functional self-healing system implemented on a power grid will react autonomously when a threat or fault occurs, without requiring human intervention to restore power to communities and preserve critical services after power outages or defects. This paper presents the existing vulnerabilities, threats, and challenges and critically analyses the current self-healing theories and methods that use machine learning for cyber–physical systems

    Contribuciones a la interoperabilidad continua entre humanos y sistemas automatizados sujetos al paradigma del Internet de las Cosas

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    Este trabajo se enmarca en el amplio contexto del Internet de las Cosas, y se centra en la interoperabilidad entre humanos y los sistemas de automatización. En cómo los dispositivos que rodean al usuario interactúan con los elementos computacionales que encuentran en su entorno, pudiendo generar, de forma automática, tareas que sean delegables a otros elementos. Siendo más concretos, la intención de este trabajo es doble. En primer lugar, proponer una arquitectura, basada en el uso de microservicios, gracias a la cual poder migrar las tareas presentes en los dispositivos cercanos al usuario a otros dentro del mismo entorno. En segundo lugar, desarrollar un sistema que haga posible la interacción del usuario con la arquitectura, permitiendo dar instrucciones al entorno a través del lenguaje natural. El desarrollo de arquitecturas basadas en microservicios posibilita la migración de un dispositivo a otro de determinadas piezas de software ligeras. Para realizar estas migraciones de la manera más óptima posible, es necesario conocer la compatibilidad entre microservicios y dispositivos. Este trabajo proporciona una manera de determinar esta compatibilidad. La interacción entre un usuario y su entorno a través del lenguaje natural está muy presente en nuestro día a día, por ejemplo, a través de asistentes virtuales de voz. Se trata de un mecanismo que busca facilitar la interacción entre humano y entorno, pero que, en determinadas situaciones, puede no responder de forma acertada a las peticiones del usuario. Una de las razones por las que se pueden dar estas situaciones es la falta de compresión de la petición dada porque no se han utilizado los términos adecuados. Otra de las razones es la falta de una definición más precisa del entorno donde es posible que coexistan diferentes elementos que, aún siendo diferentes, pueden satisfacer de una forma similar los deseos del usuario dando lugar a posibles confusiones. Que un usuario sea capaz de dar órdenes a un entorno sin necesidad de conocer el lenguaje o los patrones necesarios para que un sistema las entienda, aumenta el número de usuarios que son capaces de interactuar con su entorno. En este trabajo se presenta un sistema que pretende eliminar la necesidad de entrenamiento previo del mismo, así como el requisito, por parte del usuario, de conocer los enunciados o palabras clave necesarias para generar órdenes. A continuación se presentan las principales contribuciones en este contexto: Proposición de un conjunto de directrices que forman el marco teórico para el despliegue de una arquitectura basada en microservicios que ayudan a la descentralización del análisis de los diferentes dispositivos que coexisten en ella, así como al análisis de los diferentes microservicios presentes en la misma. Proposición de un conjunto de directrices que forman el marco teórico para el despliegue de infraestructuras efímeras, en arquitecturas basadas en microservicios, que ayudan a simplificar la toma de decisiones tanto en su despliegue como en sus migraciones. En concreto, permitiendo generar entornos donde llevar a cabo diferentes análisis de rendimiento en los dispositivos capaces de alojar un microservicio, añadiendo así un método con el que obtener datos para la toma de decisiones. Proposición de un conjunto de directrices que forman el marco teórico para el análisis de órdenes dadas en lenguaje natural por parte de un usuario humano a su entorno cercano. Proposición de un conjunto de directrices que forman el marco teórico que facilita el desarrollo de servicios compatibles con la utilización del lenguaje natural para su uso. Proposición de un conjunto de directrices que forman el marco teórico que permite, a los desarrolladores, incorporar la información necesaria sobre sus servicios y las acciones que se pueden realizar gracias a ellos, permitiendo una interacción fluida sin añadir complejidad al lenguaje que se debe utilizar. Proposición de un conjunto de directrices que forman el marco teórico que facilita la virtualización de las acciones realizables en un entorno a través del análisis de las descripciones provistas por sus desarrolladores. Proposición de un conjunto de directrices que forman el marco teórico que pretende eliminar la necesidad de entrenamiento, tanto del entorno, como de los usuarios, para poder relacionar la intención del usuario y la acción que pretende llevar a cabo. Implementación, como prueba de concepto, de una arquitectura de microservicios que sigue las directrices expuestas en este trabajo, donde la toma de decisiones sobre sus migraciones responde, tanto a la posibilidad de despliegue de programas ligeros y de corta duración para el análisis de rendimiento, así como a los deseos expuestos por usuarios potenciales a través del lenguaje natural.Parte del contenido se desarrolló como línea de investigación en varios proyectos de I+D, denominados: INRISCO: Monitorización de Incidentes en Comunidades Inteligentes: Seguridad y Movilidad (TEC2014-54335-C4-2-R) MAGOS: Secure Smart Grid Using Open Source Intelligence (TEC2017- 84197-C4-3-R) CYNAMON co-financed by European Structural Funds (ESF end FEDER) (P2018/TCS-4566)Programa de Doctorado en Ingeniería Telemática por la Universidad Carlos III de MadridPresidente: Carlos García Rubio.- Secretario: José María Flores Arias.- Vocal: Ramona Ruiz Blázque

    Learning disentangled speech representations

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    A variety of informational factors are contained within the speech signal and a single short recording of speech reveals much more than the spoken words. The best method to extract and represent informational factors from the speech signal ultimately depends on which informational factors are desired and how they will be used. In addition, sometimes methods will capture more than one informational factor at the same time such as speaker identity, spoken content, and speaker prosody. The goal of this dissertation is to explore different ways to deconstruct the speech signal into abstract representations that can be learned and later reused in various speech technology tasks. This task of deconstructing, also known as disentanglement, is a form of distributed representation learning. As a general approach to disentanglement, there are some guiding principles that elaborate what a learned representation should contain as well as how it should function. In particular, learned representations should contain all of the requisite information in a more compact manner, be interpretable, remove nuisance factors of irrelevant information, be useful in downstream tasks, and independent of the task at hand. The learned representations should also be able to answer counter-factual questions. In some cases, learned speech representations can be re-assembled in different ways according to the requirements of downstream applications. For example, in a voice conversion task, the speech content is retained while the speaker identity is changed. And in a content-privacy task, some targeted content may be concealed without affecting how surrounding words sound. While there is no single-best method to disentangle all types of factors, some end-to-end approaches demonstrate a promising degree of generalization to diverse speech tasks. This thesis explores a variety of use-cases for disentangled representations including phone recognition, speaker diarization, linguistic code-switching, voice conversion, and content-based privacy masking. Speech representations can also be utilised for automatically assessing the quality and authenticity of speech, such as automatic MOS ratings or detecting deep fakes. The meaning of the term "disentanglement" is not well defined in previous work, and it has acquired several meanings depending on the domain (e.g. image vs. speech). Sometimes the term "disentanglement" is used interchangeably with the term "factorization". This thesis proposes that disentanglement of speech is distinct, and offers a viewpoint of disentanglement that can be considered both theoretically and practically

    Educating Sub-Saharan Africa:Assessing Mobile Application Use in a Higher Learning Engineering Programme

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    In the institution where I teach, insufficient laboratory equipment for engineering education pushed students to learn via mobile phones or devices. Using mobile technologies to learn and practice is not the issue, but the more important question lies in finding out where and how they use mobile tools for learning. Through the lens of Kearney et al.’s (2012) pedagogical model, using authenticity, personalisation, and collaboration as constructs, this case study adopts a mixed-method approach to investigate the mobile learning activities of students and find out their experiences of what works and what does not work. Four questions are borne out of the over-arching research question, ‘How do students studying at a University in Nigeria perceive mobile learning in electrical and electronic engineering education?’ The first three questions are answered from qualitative, interview data analysed using thematic analysis. The fourth question investigates their collaborations on two mobile social networks using social network and message analysis. The study found how students’ mobile learning relates to the real-world practice of engineering and explained ways of adapting and overcoming the mobile tools’ limitations, and the nature of the collaborations that the students adopted, naturally, when they learn in mobile social networks. It found that mobile engineering learning can be possibly located in an offline mobile zone. It also demonstrates that investigating the effectiveness of mobile learning in the mobile social environment is possible by examining users’ interactions. The study shows how mobile learning personalisation that leads to impactful engineering learning can be achieved. The study shows how to manage most interface and technical challenges associated with mobile engineering learning and provides a new guide for educators on where and how mobile learning can be harnessed. And it revealed how engineering education can be successfully implemented through mobile tools
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