4,130 research outputs found
Mobile Device Background Sensors: Authentication vs Privacy
The increasing number of mobile devices in recent years has caused the collection of a large amount of personal information that needs to be protected. To this aim, behavioural biometrics has become very popular. But, what is the discriminative power of mobile behavioural biometrics in real scenarios? With the success of Deep Learning (DL), architectures based on Convolutional Neural Networks (CNNs) and Recurrent Neural Networks (RNNs), such as Long Short-Term Memory (LSTM), have shown improvements compared to traditional machine learning methods. However, these DL architectures still have limitations that need to be addressed. In response, new DL architectures like Transformers have emerged. The question is, can these new Transformers outperform previous biometric approaches? To answers to these questions, this thesis focuses on behavioural biometric authentication with data acquired from mobile background sensors (i.e., accelerometers and gyroscopes). In addition, to the best of our knowledge, this is the first thesis that explores and proposes novel behavioural biometric systems based on Transformers, achieving state-of-the-art results in gait, swipe, and keystroke biometrics. The adoption of biometrics requires a balance between security and privacy. Biometric modalities provide a unique and inherently personal approach for authentication. Nevertheless, biometrics also give rise to concerns regarding the invasion of personal privacy. According to the General Data Protection Regulation (GDPR) introduced by the European Union, personal data such as biometric data are sensitive and must be used and protected properly. This thesis analyses the impact of sensitive data in the performance of biometric systems and proposes a novel unsupervised privacy-preserving approach. The research conducted in this thesis makes significant contributions, including: i) a comprehensive review of the privacy vulnerabilities of mobile device sensors, covering metrics for quantifying privacy in relation to sensitive data, along with protection methods for safeguarding sensitive information; ii) an analysis of authentication systems for behavioural biometrics on mobile devices (i.e., gait, swipe, and keystroke), being the first thesis that explores the potential of Transformers for behavioural biometrics, introducing novel architectures that outperform the state of the art; and iii) a novel privacy-preserving approach for mobile biometric gait verification using unsupervised learning techniques, ensuring the protection of sensitive data during the verification process
Displacement and the Humanities: Manifestos from the Ancient to the Present
This is the final version. Available on open access from MDPI via the DOI in this recordThis is a reprint of articles from the Special Issue published online in the open access journal Humanities (ISSN 2076-0787) (available at: https://www.mdpi.com/journal/humanities/special_issues/Manifestos Ancient Present)This volume brings together the work of practitioners, communities, artists and other researchers from multiple disciplines. Seeking to provoke a discourse around displacement within and beyond the field of Humanities, it positions historical cases and debates, some reaching into the ancient past, within diverse geo-chronological contexts and current world urgencies. In adopting an innovative dialogic structure, between practitioners on the ground - from architects and urban planners to artists - and academics working across subject areas, the volume is a proposition to: remap priorities for current research agendas; open up disciplines, critically analysing their approaches; address the socio-political responsibilities that we have as scholars and practitioners; and provide an alternative site of discourse for contemporary concerns about displacement. Ultimately, this volume aims to provoke future work and collaborations - hence, manifestos - not only in the historical and literary fields, but wider research concerned with human mobility and the challenges confronting people who are out of place of rights, protection and belonging
Cultures of Citizenship in the Twenty-First Century: Literary and Cultural Perspectives on a Legal Concept
In the early twenty-first century, the concept of citizenship is more contested than ever. As refugees set out to cross the Mediterranean, European nation-states refer to "cultural integrity" and "immigrant inassimilability," revealing citizenship to be much more than a legal concept. The contributors to this volume take an interdisciplinary approach to considering how cultures of citizenship are being envisioned and interrogated in literary and cultural (con)texts. Through this framework, they attend to the tension between the citizen and its spectral others - a tension determined by how a country defines difference at a given moment
An information system for a multiplayer geolocation game
Mestrado de dupla diplomação com a National Polytechnic University of ArméniaA great deal of travel can educate tourists. As tourism becomes more accessible, many new technologies are being used to provide interesting, appealing, and efficient trips so that travelers can find what they want, avoid getting lost, and get the most out of their trip. Science, education, and culture all benefit from technological advancement. As many good ideas can now be turned into reality, interactive education has found a place in everyday life. Research and review of geolocation-based applications (such as hiking path providers) and guide applications were conducted to better understand the technologies and tools related
to the topic. The best features were designed to solve the problem after summarizing the results of applications, their advantages and disadvantages. The purpose of this paper is to create a geolocation-based game that will allow travelers to explore nearby attractions, learn about local culture, and broaden their knowledge while traveling. To summarize, a dynamic platform that can be implemented in a variety of ways was created.Uma grande quantidade de viagens pode educar os turistas. Ă€ medida que o turismo se torna mais acessĂvel, muitas novas tecnologias estĂŁo sendo usadas para fornecer viagens interessantes, atraentes e eficientes para que os viajantes possam encontrar o que desejam, evitar se perder e aproveitar ao máximo sua viagem. CiĂŞncia, educação e cultura se beneficiam do avanço tecnolĂłgico. No muitas boas ideias podem agora se tornar realidade, a educação interativa encontrou um lugar na vida cotidiana. Pesquisa e revisĂŁo de aplicativos baseados em geolocalização (como provedores de trilhas para caminhadas) e aplicativos de guia foram realizados para entender melhor as tecnologias e ferramentas relacionadas ao tema. As melhores funcionalidades foram projetadas para solucionar o problema apĂłs resumir os resultados das aplicações, suas vantagens e desvantagens. O objetivo deste artigo Ă© criar um jogo baseado em geolocalização que permita aos viajantes explorar atrações prĂłximas, aprender sobre a cultura local e ampliar seus conhecimentos durante a viagem. Para resumir, foi criada uma plataforma dinâmica que pode ser implementada de várias maneiras
Plant Ontology, The Amazonian Yachag and the Artist in Trance
The commonalities that plants, shamans and artists share may not be evident at first glance, nevertheless, if we search for uncomfortable entanglements and difficult questions, we may find that for centuries the voice with which plants speak has been the Amazonian yachag and the chamana or healer. Furthermore, who has invariably accompanied different plateaus along humanity’s convoluted becomings, has been what I have called the artist in trance. This artist is a concoction born from Walter Benjamin’s notion of ecstatic trance and Nietzche’s tragic artist. In this research I have investigated the being of plants or plant ontology and how they may be others who we may learn from in order to relate to Earth in a better way. The artist-yachag or artist philosopher as we may call her, is the one who bridges disparate conocimientos or knowledge, those of plants and those of shamans and translates them into our own words and worlds. What for? To learn to inhabit this planet in a softermood, in a weak mood as Gianni Vattimo and Santiago Zabala would say, stemming from other visions and other perspectives. The interconnectivity that plants generate, as well as the idea of them being a world in themselves allied with the yachag or shaman and the artist, may lead humanity towards the understanding of a world to come. Applyingand expanding the notion first posited by Levi-Strauss and then contested by Viveiros de Castro that the relation between nature and culture is one of“metonymic contiguity rather than metaphoric resemblance”, I argue that the same kind of contiguity exists between plants,the Amazonian yachag and the artist in trance. The trope ofmetonymic contiguity serves to connect in a continuum these three entities one after the other in a nature-culture effervescent symbiosis.
‍https://digitalmaine.com/academic/1047/thumbnail.jp
Under construction: infrastructure and modern fiction
In this dissertation, I argue that infrastructural development, with its technological promises but widening geographic disparities and social and environmental consequences, informs both the narrative content and aesthetic forms of modernist and contemporary Anglophone fiction. Despite its prevalent material forms—roads, rails, pipes, and wires—infrastructure poses particular formal and narrative problems, often receding into the background as mere setting. To address how literary fiction theorizes the experience of infrastructure requires reading “infrastructurally”: that is, paying attention to the seemingly mundane interactions between characters and their built environments. The writers central to this project—James Joyce, William Faulkner, Karen Tei Yamashita, and Mohsin Hamid—take up the representational challenges posed by infrastructure by bringing transit networks, sanitation systems, and electrical grids and the histories of their development and use into the foreground. These writers call attention to the political dimensions of built environments, revealing the ways infrastructures produce, reinforce, and perpetuate racial and socioeconomic fault lines. They also attempt to formalize the material relations of power inscribed by and within infrastructure; the novel itself becomes an imaginary counterpart to the technologies of infrastructure, a form that shapes and constrains what types of social action and affiliation are possible
Chemistry and physics of positrons interacting with atoms, molecules, and fields
The positron is the antiparticle of the electron, possesing the same mass and obeying the same spin statistics but with an opposite charge. When a positron and an electron collide, both annihilate within a few nanoseconds, emitting two or three photons. However, positrons can also form energetically metastable states with atoms and molecules before the pair annihilation.
The relatively long positronic lifetime, on a nanosecond time scale, allows a positron to interfere with the faster molecular vibrational motions or with molecular reactions, which are typically in the range between femto- and picoseconds.
Therefore, such positronic systems expand the field of physical chemistry, which is still vastly unexplored theoretically and experimentally, and it could lead to new and exciting applications.
In recent decades, significant efforts have been made in the development of theoretical methods to accurately describe the interactions of positrons with matter, which often requires explicit many-body correlation effects, posing a substantial challenge for quantum-chemical methods based on single-particle atomic orbitals.
Despite many creative and accurate approaches, most of them are extremely computationally expensive. Therefore, their application is limited to small and highly polar molecular systems, where the binding is mainly driven by the strong attractive electrostatic interaction.
This thesis aims to attain a robust understanding of positrons interacting with molecular systems, starting from first principles of quantum mechanics.
To this end, new variational electron-positron wave function ansatzes are proposed and discussed, which are based on a combination of electron-positron geminal orbitals and a Jastrow factor that explicitly includes three- and four-body electron-positron correlations in the field of the nuclei, that is fully optimized within the framework of the Variational Monte Carlo (VMC) method.
The performance of this approach is validated in combination with the Diffusion Monte Carlo (DMC) method by calculating total energies and binding energies of a set of positronic atomic and molecular systems, demonstrating that a representation in terms of electron-positron orbitals for the fermionic and Jastrow wave functions is an accurate and efficient approach for studying the interactions of positrons with matter.
Moreover, the developed methodology is applied here to study electronic and positronic response properties such as dipole polarizabilities, annihilation lifetimes, and expectation values of interparticle distances as a function of an external electric field, aiming to gain further physical insights into the electron-positron wave function structure.
Through the Quantum Monte Carlo (QMC) method, non-trivial variations of the polarizabilities with respect to the interatomic length were unveiled.
A further decomposition of the polarizability into electronic and positronic contributions revealed that the positronic cloud in the outer regions is highly polarizable and screens the response of the electrons to the same external electric field.
Furthermore, the QMC methodology was employed to investigate the stability of
a system consisting of two positrons and three hydride anions, discovering the formation of a three-center two-positron bond, analogous to the well-known three-center two-electron counterpart in Li, thus extending the concept of positron-bonded molecules, in which two or more repelling anions are stabilized by one or more positrons.
The final section is dedicated to the exploration of using positron-bonded diatomic systems as an alternative approach for estimating interacting atomic sizes, in which it was found that their equilibrium distance is connected to the sum of van der Waals radii of the corresponding neutral atoms, and to a lesser extent to the sum of anionic radii.
Overall, this thesis presents the development of a computational methodology based on QMC techniques to compute and analyze the wave function of positrons interacting with atoms, molecules, and external electric fields.
The methods and analysis developed in the presented work will pave the way for further study of complex positronic systems of physical and chemical interest, encouraging new theoretical and experimental investigations in the field of positron-matter interactions.Positrons Interacting with Molecules and positronic chemistr
Machine learning and mixed reality for smart aviation: applications and challenges
The aviation industry is a dynamic and ever-evolving sector. As technology advances and becomes more sophisticated, the aviation industry must keep up with the changing trends. While some airlines have made investments in machine learning and mixed reality technologies, the vast majority of regional airlines continue to rely on inefficient strategies and lack digital applications. This paper investigates the state-of-the-art applications that integrate machine learning and mixed reality into the aviation industry. Smart aerospace engineering design, manufacturing, testing, and services are being explored to increase operator productivity. Autonomous systems, self-service systems, and data visualization systems are being researched to enhance passenger experience. This paper investigate safety, environmental, technological, cost, security, capacity, and regulatory challenges of smart aviation, as well as potential solutions to ensure future quality, reliability, and efficiency
- …