4,232 research outputs found

    Mobile Device Background Sensors: Authentication vs Privacy

    Get PDF
    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

    Complementarities in human capital production:The Importance of Gene-Environment Interactions

    Get PDF

    An examination of the verbal behaviour of intergroup discrimination

    Get PDF
    This thesis examined relationships between psychological flexibility, psychological inflexibility, prejudicial attitudes, and dehumanization across three cross-sectional studies with an additional proposed experimental study. Psychological flexibility refers to mindful attention to the present moment, willing acceptance of private experiences, and engaging in behaviours congruent with one’s freely chosen values. Inflexibility, on the other hand, indicates a tendency to suppress unwanted thoughts and emotions, entanglement with one’s thoughts, and rigid behavioural patterns. Study 1 found limited correlations between inflexibility and sexism, racism, homonegativity, and dehumanization. Study 2 demonstrated more consistent positive associations between inflexibility and prejudice. And Study 3 controlled for right-wing authoritarianism and social dominance orientation, finding inflexibility predicted hostile sexism and racism beyond these factors. While showing some relationships, particularly with sexism and racism, psychological inflexibility did not consistently correlate with varied prejudices across studies. The proposed randomized controlled trial aims to evaluate an Acceptance and Commitment Therapy intervention to reduce sexism through enhanced psychological flexibility. Overall, findings provide mixed support for the utility of flexibility-based skills in addressing complex societal prejudices. Research should continue examining flexibility integrated with socio-cultural approaches to promote equity

    Distributed Ledger Technology (DLT) Applications in Payment, Clearing, and Settlement Systems:A Study of Blockchain-Based Payment Barriers and Potential Solutions, and DLT Application in Central Bank Payment System Functions

    Get PDF
    Payment, clearing, and settlement systems are essential components of the financial markets and exert considerable influence on the overall economy. While there have been considerable technological advancements in payment systems, the conventional systems still depend on centralized architecture, with inherent limitations and risks. The emergence of Distributed ledger technology (DLT) is being regarded as a potential solution to transform payment and settlement processes and address certain challenges posed by the centralized architecture of traditional payment systems (Bank for International Settlements, 2017). While proof-of-concept projects have demonstrated the technical feasibility of DLT, significant barriers still hinder its adoption and implementation. The overarching objective of this thesis is to contribute to the developing area of DLT application in payment, clearing and settlement systems, which is still in its initial stages of applications development and lacks a substantial body of scholarly literature and empirical research. This is achieved by identifying the socio-technical barriers to adoption and diffusion of blockchain-based payment systems and the solutions proposed to address them. Furthermore, the thesis examines and classifies various applications of DLT in central bank payment system functions, offering valuable insights into the motivations, DLT platforms used, and consensus algorithms for applicable use cases. To achieve these objectives, the methodology employed involved a systematic literature review (SLR) of academic literature on blockchain-based payment systems. Furthermore, we utilized a thematic analysis approach to examine data collected from various sources regarding the use of DLT applications in central bank payment system functions, such as central bank white papers, industry reports, and policy documents. The study's findings on blockchain-based payment systems barriers and proposed solutions; challenge the prevailing emphasis on technological and regulatory barriers in the literature and industry discourse regarding the adoption and implementation of blockchain-based payment systems. It highlights the importance of considering the broader socio-technical context and identifying barriers across all five dimensions of the social technical framework, including technological, infrastructural, user practices/market, regulatory, and cultural dimensions. Furthermore, the research identified seven DLT applications in central bank payment system functions. These are grouped into three overarching themes: central banks' operational responsibilities in payment and settlement systems, issuance of central bank digital money, and regulatory oversight/supervisory functions, along with other ancillary functions. Each of these applications has unique motivations or value proposition, which is the underlying reason for utilizing in that particular use case

    Measuring socioeconomic position in studies of health inequalities

    Get PDF
    There is a consistent finding that the higher the socioeconomic position (SEP), the better the health. The choice of SEP indicator is crucial in explaining these socioeconomic inequalities. However, a poorly motivated use of SEP indicators prevails in the literature on social health inequalities, hampering the transparency and comparability across studies. Its primary aim is to explore different ways of measuring SEP to identify social inequalities in health. The thesis focuses on the most common, objective SEP indicators (education, occupation, and income); subjective SEP; and childhood circumstances. This thesis consists of three papers. Papers I and III apply data from the Tromsø Study, and Paper II is based on an online survey investigating people's views on SEP, conducted in Norway and Australia. Paper I investigates the potential to combine education and income into a composite score for SEP and how it predicts inequalities in health-related quality of life (HRQoL). Paper II assesses the relative importance of objective SEP indicators and childhood circumstances in estimating subjective SEP. Paper III explores the role of circumstances and lifestyle factors in estimating inequalities in HRQoL and self-rated health. While we found that the combination of education and income demonstrated a non-linear relationship with overall SEP, the composite SEP score was not superior as a predictor of HRQoL compared to including education and income separately. Furthermore, we found that childhood circumstances demonstrated a lasting, independent impact on subjective SEP. Paper III revealed that there were inequalities arising from circumstances, with substantial contributions from financial circumstances in childhood and education. This thesis demonstrates the need to motivate the choice of SEP indicator in studies of health inequalities. It also stresses the importance of early-life factors as determinants of adult health, advocating for policies targeting childhood circumstances in equalising early life chances.Et svært vanlig funn på tvers av land, studiepopulasjoner og helseutfall er at desto høyere sosioøkonomisk posisjon (SEP), desto bedre helse. Valg av SEP-indikator som skal reflektere de sosioøkonomiske dimensjonene i helse er avgjørende for å forklare disse helseulikhetene. Likevel er det slik at bruken av SEP-indikatorer i studier om sosial ulikhet i helse ofte preges av svak eller ingen begrunnelse med utgangspunkt i teori og hypoteser, noe som begrenser muligheten til sammenligning mellom studier. Denne avhandlingen bruker ulike tilnærminger for å måle SEP i studier av helseulikhet. Et overordnet formål er å utforske ulike måter å måle sosial posisjon for å identifisere sosiale ulikhet i helse, og hvordan livsstilsfaktorer i tillegg påvirker dette forholdet. Fokuset vil være på de tre vanligste objektive SEP-indikatorene (utdanning, yrke og inntekt); subjektiv SEP; og indikatorer for barndomsforhold. Avhandlingen består av tre artikler. Artikkel I og III er basert på data fra Tromsøundersøkelsen, mens Artikkel II benytter data fra på en nettbasert spørreundersøkelse om folks betraktninger omkring SEP, som har blitt gjennomført i Norge og Australia. Alle de tre artiklene utforsker bruken av ulike SEP-indikatorer i en helseulikhetssammenheng. Artikkel I undersøker potensialet for å kombinere utdanning og inntekt til en samleindikator for SEP, samt hvordan denne samleindikatoren predikerer helse-relatert livskvalitet (HRQoL). Artikkel II måler objektive SEP-indikatorer (utdanning, yrke og inntekt) og barndomsforholds relative betydning i å estimere subjektiv SEP. Artikkel III utforsker hvordan variabler om barndomsforhold på den ene siden og livsstilsfaktorer på den andre estimerer HRQoL og selvrapportert helse, både på et bestemt tidspunkt og over tid. Vi fant at kombinasjonen av utdanning og inntekt viste en sterk ikke-lineær sammenheng med total SEP, mens samleindikatoren for SEP viste seg å ikke være bedre i å predikere HRQoL sammenlignet med å inkludere utdanning og inntekt separat. Videre fant vi at barndomsforhold så ut til å ha en vedvarende påvirkning på subjektiv SEP, som var uavhengig av objektiv SEP. Artikkel III viste at det var ulikheter i helse med røtter i barndomsforhold, med særlig påvirkning fra økonomiske forhold i barndommen og egen utdanning. Denne avhandlingen viser behovet for å gjøre et faglig motivert valg av SEP-indikator i studier av helseulikhet. Den understreker også viktigheten av barndomsforhold som bestemmende faktorer for helseutfall senere i livet, og etterlyser dermed politikk rettet mot tidlige barndomsforhold for å utjevne ulikheter og sikre gode livssjanser

    Complementarities in human capital production:The Importance of Gene-Environment Interactions

    Get PDF

    Safe passage for attachment systems:Can attachment security at international schools be measured, and is it at risk?

    Get PDF
    Relocations challenge attachment networks. Regardless of whether a person moves or is moved away from, relocation produces separation and loss. When such losses are repeatedly experienced without being adequately processed, a defensive shutting down of the attachment system could result, particularly when such experiences occur during or across the developmental years. At schools with substantial turnover, this possibility could be shaping youth in ways that compromise attachment security and young people’s willingness or ability to develop and maintain deep long-term relationships. Given the well-documented associations between attachment security, social support, and long-term physical and mental health, the hypothesis that mobility could erode attachment and relational health warrants exploration. International schools are logical settings to test such a hypothesis, given their frequently high turnover without confounding factors (e.g. war trauma or refugee experiences). In addition, repeated experiences of separation and loss in international school settings would seem likely to create mental associations for the young people involved regarding how they and others tend to respond to such situations in such settings, raising the possibility that people at such schools, or even the school itself, could collectively be represented as an attachment figure. Questions like these have received scant attention in the literature. They warrant consideration because of their potential to shape young people’s most general convictions regarding attachment, which could, in turn, have implications for young people’s ability to experience meaning in their lives

    LIPIcs, Volume 251, ITCS 2023, Complete Volume

    Get PDF
    LIPIcs, Volume 251, ITCS 2023, Complete Volum

    Differences in well-being:the biological and environmental causes, related phenotypes, and real-time assessment

    Get PDF
    Well-being is a complex, and multifaceted construct that includes feeling good and functioning well. There is a growing global recognition of well-being as an important research topic and public policy goal. Well-being is related to less behavioral and emotional problems, and is associated with many positive aspects of daily life, including longevity, higher educational achievement, happier marriage, and more productivity at work. People differ in their levels of well-being, i.e., some people are in general happier or more satisfied with their lives than others. These individual differences in well-being can arise from many different factors, including biological (genetic) influences and environmental influences. To enhance the development of future mental health prevention and intervention strategies to increase well-being, more knowledge about these determinants and factors underlying well-being is needed. In this dissertation, I aimed to increase the understanding of the etiology in a series of studies using different methods, including systematic reviews, meta-analyses, twin designs, and molecular genetic designs. In part I, we brought together all published studies on the neural and physiological factors underlying well-being. This overview allowed us to critically investigate the claims made about the biology involved in well-being. The number of studies on the neural and physiological factors underlying well-being is increasing and the results point towards potential correlates of well-being. However, samples are often still small, and studies focus mostly on a single biomarker. Therefore, more well-powered, data-driven, and integrative studies across biological categories are needed to better understand the neural and physiological pathways that play a role in well-being. In part II, we investigated the overlap between well-being and a range of other phenotypes to learn more about the etiology of well-being. We report a large overlap with phenotypes including optimism, resilience, and depressive symptoms. Furthermore, when removing the genetic overlap between well-being and depressive symptoms, we showed that well-being has unique genetic associations with a range of phenotypes, independently from depressive symptoms. These results can be helpful in designing more effective interventions to increase well-being, taking into account the overlap and possible causality with other phenotypes. In part III, we used the extreme environmental change during the COVID-19 pandemic to investigate individual differences in the effects of such environmental changes on well-being. On average, we found a negative effect of the pandemic on different aspects of well-being, especially further into the pandemic. Whereas most previous studies only looked at this average negative effect of the pandemic on well-being, we focused on the individual differences as well. We reported large individual differences in the effects of the pandemic on well-being in both chapters. This indicates that one-size-fits-all preventions or interventions to maintain or increase well-being during the pandemic or lockdowns will not be successful for the whole population. Further research is needed for the identification of protective factors and resilience mechanisms to prevent further inequality during extreme environmental situations. In part IV, we looked at the real-time assessment of well-being, investigating the feasibility and results of previous studies. The real-time assessment of well-being, related variables, and the environment can lead to new insights about well-being, i.e., results that we cannot capture with traditional survey research. The real-time assessment of well-being is therefore a promising area for future research to unravel the dynamic nature of well-being fluctuations and the interaction with the environment in daily life. Integrating all results in this dissertation confirmed that well-being is a complex human trait that is influenced by many interrelated and interacting factors. Future directions to understand individual differences in well-being will be a data-driven approach to investigate the complex interplay of neural, physiological, genetic, and environmental factors in well-being

    Machine Unlearning: A Survey

    Full text link
    Machine learning has attracted widespread attention and evolved into an enabling technology for a wide range of highly successful applications, such as intelligent computer vision, speech recognition, medical diagnosis, and more. Yet a special need has arisen where, due to privacy, usability, and/or the right to be forgotten, information about some specific samples needs to be removed from a model, called machine unlearning. This emerging technology has drawn significant interest from both academics and industry due to its innovation and practicality. At the same time, this ambitious problem has led to numerous research efforts aimed at confronting its challenges. To the best of our knowledge, no study has analyzed this complex topic or compared the feasibility of existing unlearning solutions in different kinds of scenarios. Accordingly, with this survey, we aim to capture the key concepts of unlearning techniques. The existing solutions are classified and summarized based on their characteristics within an up-to-date and comprehensive review of each category's advantages and limitations. The survey concludes by highlighting some of the outstanding issues with unlearning techniques, along with some feasible directions for new research opportunities
    • …
    corecore