1,722,791 research outputs found
Privacy-Friendly De-Authentication with BLUFADE: Blurred Face Detection
No full textIdeally, secure user sessions should start and end with authentication and de-Authentication phases, respectively. While the user must pass the former to start a secure session, the latter's importance is often ignored or underestimated. Dangling or unattended sessions expose users to well-known Lunchtime Attacks. To mitigate this threat, the research community focused on automated de-Authentication systems. Unfortunately, no single approach offers security, privacy, and usability. For instance, although facial recognition-based methods might be a good fit for security and usability, they violate user privacy by constantly recording the user and the surrounding environment.In this work, we propose BLUFADE, a fast, secure, and transparent de-Authentication system that takes advantage of blurred faces to preserve user privacy. We obfuscate a webcam with a physical blur layer and use deep learning algorithms to perform face detection continuously. To assess BLUFADE's practicality, we collected two datasets formed by 30 recruited subjects (users) and thousands of physically blurred celebrity photos. The former was used to train and evaluate the deauthentication system performances, the latter to assess the privacy and to increase variance in training data. We show that our approach outperforms state-of-The-Art methods in detecting blurred faces, achieving up to 95% accuracy. Furthermore, we demonstrate that BLUFADE effectively de-Authenticates users up to 100% accuracy in under 3 seconds, while satisfying security, privacy, and usability requirements.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Cyber Securit
Development of microfluidic-based 3D bioprinting systems to create hierarchical in vitro models of human tissues
No full textMicrofluidics is rapidly revolutionizing the scientific panorama, providing unmatched high-throughput platforms that find application in numerous areas of physics, chemistry, biology, and material science. In the context of tissue engineering, microfluidic chips have been proposed, in combination with bioactive materials, as promising tools for spinning cell-laden fibers with on-demand characteristics. However, cells encapsulated in filaments produced via microfluidic spinning technology (MST) are confined in a quasi-3D environment that fails to replicate the intricate 3D architecture of biological tissues. The recent synergistic combination of 3D bioprinting with microfluidic devices enables to create sophisticated microfibers and arrange them in 3D to realize three-dimensional functional replicas of human tissues.
It is pivotal to mimic the structural heterogeneities of native tissues in terms of material composition, cell type, cell density and microstructural properties in order to realize functional 3D tissue models. In fact, these factors have a significant impact on both mechanical properties and the biological outcome. Recently, microfluidic-based systems have emerged as advanced tools to control in one-step the production of microfibers with tailored dimension, composition, and morphology. More specifically, microfluidic devices can be used to control fiber properties in real time through microchannels where various components can be mixed, split or emulsified. Ultimately, the macro-architectural control of 3D constructs is made possible by the coupling of microfluidic chips with a 3D printing system.
In this work, we report the fabrication of a series of novel extrusion-based microfluidic printing heads that enable the spinning and deposition of microfibers with tailored characteristics in a three-dimensional environment. These tools allow for the 3D printing of fiber-based scaffolds with adjustable intra-fiber composition, cell density and microporosity. The study aims to realize functionally graded structures that simulate the change in properties (e.g., material composition, cell density, cell type population and microporosity) observed at the interface of two different tissues. Mechanical and morphological analysis have been carried out to evaluate the resulting internal microstructure, while the biological response of embedded cells was monitored with biological and biochemical assays that allow to investigate cell viability, expression of target proteins and production of specific enzymes, confirming the differentiation of bioprinted stem cells
Simulation Environment for Mixed AHB-NoC Architectures
No full textCommunication architecture is crucial for performances and power constraints in modern multicore systems on chip (SoC). Network-on-Chip (NoC) is used to increase the bandwidth limitations of a traditional bus paradigm. In this work an interface between the AMBA-AHB bus and NoC has been designed. A NoC simulation environment has been modified integrating the AHB architectures in different NoC architectures. The performances of different heterogeneous (AHB-NoC) architectures have been compared
EVO-NFC: Extra Virgin Olive Oil Traceability Using NFC Suitable for Small-Medium Farms
Full text linkFood traceability is a fundamental requirement for the agriculture of the future. A food traceability system should ensure food safety and quality control, allow authentication, fraud prevention and control by the authority, improve consumers' safety and confidence. The agri-food supply chain is complex and difficult to handle due to the presence of various stakeholders and control authorities. Consequently, the complexity and the cost of traceability systems make it inapplicable for small and medium enterprises (SMEs). This work defines of a food traceability system using existing low cost digital technologies with the possibility to be integrated into a database for public authority controls. Smartphone applications allow consumer involvement and a bidirectional interaction between the company and the consumer. This work proposes the use of smartphone with NFC technology in every phase of the food chain bringing the information to the final consumer. An advantage of the proposed system is the low cost and easy to use, allowing its diffusion in small and micro farms, regional typical products, bio productions. The applications developed and the database architecture have been customized to the extra virgin olive oil process. Final considerations evidence the economic advantage of the traceability system
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dynamic Backdoors with Global Average Pooling
No full textOutsourced training and machine learning as a service have resulted in novel
attack vectors like backdoor attacks. Such attacks embed a secret functionality
in a neural network activated when the trigger is added to its input. In most
works in the literature, the trigger is static, both in terms of location and
pattern. The effectiveness of various detection mechanisms depends on this
property. It was recently shown that countermeasures in image classification,
like Neural Cleanse and ABS, could be bypassed with dynamic triggers that are
effective regardless of their pattern and location. Still, such backdoors are
demanding as they require a large percentage of poisoned training data. In this
work, we are the first to show that dynamic backdoor attacks could happen due
to a global average pooling layer without increasing the percentage of the
poisoned training data. Nevertheless, our experiments in sound classification,
text sentiment analysis, and image classification show this to be very
difficult in practice
Video for Food Traceability in Fruit and Vegetables Supply Chain
No full textFood traceability is a fundamental requirement for the agriculture of the future. The project proposed in this work uses smartphones with NFC technology in every phase of the food supply chain (production, processing, distribution and consumption) bringing the information to the final consumer. The architecture consists of a complex identification system, which transmits data to a database through apps on android smartphones during all phases of the production process. Data storage in the cloud allows information to be shared among farmers involved in the same production chain, with agricultural consortia with government institutions and with final consumers
Internet-of-Forensic (IoF): A blockchain based digital forensics framework for IoT applications
No full textDigital forensic in Internet-of-Thing (IoT) paradigm is critical due to its heterogeneity and lack of transparency of evidence processing. Moreover, cross-border legalization makes a hindrance in such process pertaining to the cloud forensic issues. This urges a forensic framework for IoT which provides distributed computing, decentralization, and transparency of forensic investigation of digital evidences in cross-border perspectives. To this end, we propose a framework for IoT forensics that addresses the above mentioned issues. The proposed solution called Internet-of-Forensics (IoF) considers a blockchain tailored IoT framework for digital forensics. It provides a transparent view of the investigation process that involves all the stakeholders (e.g., heterogeneous devices, and cloud service providers) in a single framework. It uses blockchain-based case chain to deal with the investigation process including chain-of-custody and evidence chain. Consensus is used for consortium to solve the problems of cross-border legalization. This is also beneficial for a transparent and ease of forensic reference. The programmable lattice-based cryptographic primitives produce reduced complexities. It shows benefits for power-aware devices and puts an add-on to the novelty of the presented idea. IoF is generic; hence, it can be used by autonomous security operation centers, cyber-forensic investigators and manually initiated evidences under chain-of-custody for man-made crimes. Security services are assured as required by the framework. IoF is experimented and compared with the other state-of-the-art frameworks. The outcomes and analysis prove the efficiency of IoF concerning complexity, time consumption, memory and CPU utilization, gas consumption, and energy analysis
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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