206 research outputs found
The Effect of Using Histogram Equalization and Discrete Cosine Transform on Facial Keypoint Detection
This study aims to figure out the effect of using Histogram Equalization and Discrete Cosine Transform (DCT) in detecting facial keypoints, which can be applied for 3D facial reconstruction in face recognition. Four combinations of methods comprising of Histogram Equalization, removing low-frequency coefficients using Discrete Cosine Transform (DCT) and using five feature detectors, namely: SURF, Minimum Eigenvalue, Harris-Stephens, FAST, and BRISK were used for test. Data that were used for test were obtained from Head Pose Image and ORL Databases. The result from the test were evaluated using F-score. The highest F-score for Head Pose Image Dataset is 0.140 and achieved through the combination of DCT & Histogram Equalization with feature detector SURF. The highest F-score for ORL Database is 0.33 and achieved through the combination of DCT & Histogram Equalization with feature detector BRISK
ARCHANGEL: Tamper-proofing Video Archives using Temporal Content Hashes on the Blockchain
We present ARCHANGEL; a novel distributed ledger based system for assuring
the long-term integrity of digital video archives. First, we describe a novel
deep network architecture for computing compact temporal content hashes (TCHs)
from audio-visual streams with durations of minutes or hours. Our TCHs are
sensitive to accidental or malicious content modification (tampering) but
invariant to the codec used to encode the video. This is necessary due to the
curatorial requirement for archives to format shift video over time to ensure
future accessibility. Second, we describe how the TCHs (and the models used to
derive them) are secured via a proof-of-authority blockchain distributed across
multiple independent archives. We report on the efficacy of ARCHANGEL within
the context of a trial deployment in which the national government archives of
the United Kingdom, Estonia and Norway participated.Comment: Accepted to CVPR Blockchain Workshop 201
A Design Concept for a Tourism Recommender System for Regional Development
Despite of tourism infrastructure and software, the development of tourism is hampered due to the lack of information support, which encapsulates various aspects of travel implementation. This paper highlights a demand for integrating various approaches and methods to develop a universal tourism information recommender system when building individual tourist routes. The study objective is proposing a concept of a universal information recommender system for building a personalized tourist route. The developed design concept for such a system involves a procedure for data collection and preparation for tourism product synthesis; a methodology for tourism product formation according to user preferences; the main stages of this methodology implementation. To collect and store information from real travelers, this paper proposes to use elements of blockchain technology in order to ensure information security. A model that specifies the key elements of a tourist route planning process is presented. This article can serve as a reference and knowledge base for digital business system analysts, system designers, and digital tourism business implementers for better digital business system design and implementation in the tourism sector
Image Restoration Effect on DCT High Frequency Removal and Wiener Algorithm for Detecting Facial Key Points
This study aims to figure out the effect of using Histogram Equalization and Discrete Cosine Transform (DCT) in detecting facial keypoints, which can be applied for 3D facial reconstruction in face recognition. Four combinations of methods comprising of Histogram Equalization, removing low-frequency coefficients using Discrete Cosine Transform (DCT) and using five feature detectors, namely: SURF, Minimum Eigenvalue, Harris-Stephens, FAST, and BRISK were used for test. Data that were used for test were obtained from Head Pose Image and ORL Databases. The result from the test were evaluated using F-score. The highest F-score for Head Pose Image Dataset is 0.140 and achieved through the combination of DCT & Histogram Equalization with feature detector SURF. The highest F-score for ORL Database is 0.33 and achieved through the combination of DCT & Histogram Equalization with feature detector BRISK
Decentralized Federated Learning: Fundamentals, State-of-the-art, Frameworks, Trends, and Challenges
In the last decade, Federated Learning (FL) has gained relevance in training
collaborative models without sharing sensitive data. Since its birth,
Centralized FL (CFL) has been the most common approach in the literature, where
a central entity creates a global model. However, a centralized approach leads
to increased latency due to bottlenecks, heightened vulnerability to system
failures, and trustworthiness concerns affecting the entity responsible for the
global model creation. Decentralized Federated Learning (DFL) emerged to
address these concerns by promoting decentralized model aggregation and
minimizing reliance on centralized architectures. However, despite the work
done in DFL, the literature has not (i) studied the main aspects
differentiating DFL and CFL; (ii) analyzed DFL frameworks to create and
evaluate new solutions; and (iii) reviewed application scenarios using DFL.
Thus, this article identifies and analyzes the main fundamentals of DFL in
terms of federation architectures, topologies, communication mechanisms,
security approaches, and key performance indicators. Additionally, the paper at
hand explores existing mechanisms to optimize critical DFL fundamentals. Then,
the most relevant features of the current DFL frameworks are reviewed and
compared. After that, it analyzes the most used DFL application scenarios,
identifying solutions based on the fundamentals and frameworks previously
defined. Finally, the evolution of existing DFL solutions is studied to provide
a list of trends, lessons learned, and open challenges
Fotofacesua: sistema de gestão fotográfica da Universidade de Aveiro
Nowadays, automation is present in basically every computational system. With
the raise of Machine Learning algorithms through the years, the necessity of a human
being to intervene in a system has dropped a lot. Although, in Universities,
Companies and even governmental Institutions there are some systems that are
have not been automatized. One of these cases, is the profile photo management,
that stills requires human intervention to check if the image follows the Institution
set of criteria that are obligatory to submit a new photo.
FotoFaces is a system for updating the profile photos of collaborators at the University
of Aveiro that allows the collaborator to submit a new photo and, automatically,
through a set of image processing algorithms, decide if the photo meets a set of
predifined criteria. One of the main advantages of this system is that it can be
used in any institution and can be adapted to different needs by just changing the
algorithms or criteria considered. This Dissertation describes some improvements
implemented in the existing system, as well as some new features in terms of the
available algorithms.
The main contributions to the system are the following: sunglasses detection, hat
detection and background analysis. For the first two, it was necessary to create
a new database and label it to train, validate and test a deep transfer learning
network, used to detect sunglasses and hats. In addition, several tests were performed
varying the parameters of the network and using some machine learning and
pre-processing techniques on the input images. Finally, the background analysis
consists of the implementation and testing of 2 existing algorithms in the literature,
one low level and the other deep learning.
Overall, the results obtained in the improvement of the existing algorithms, as well
as the performance of the new image processing modules, allowed the creation of
a more robust (improved production version algorithms) and versatile (addition of
new algorithms to the system) profile photo update system.Atualmente, a automação está presente em basicamente todos os sistemas computacionais.
Com o aumento dos algoritmos de Aprendizagem Máquina ao longo
dos anos, a necessidade de um ser humano intervir num sistema caiu bastante.
Embora, em Universidades, Empresas e até Instituições governamentais, existam
alguns sistemas que não foram automatizados. Um desses casos, é a gestão de
fotos de perfil, que requer intervenção humana para verificar se a imagem segue o
conjunto de critérios da Instituição que são obrigatórios para a submissão de uma
nova foto.
O FotoFaces é um sistema de atualização de fotos do perfil dos colaboradores
na Universidade de Aveiro que permite ao colaborador submeter uma nova foto
e, automaticamente, através de um conjunto de algoritmos de processamnto de
imagem, decidir se a foto cumpre um conjunto de critérios predefinidos. Uma das
principais vantagens deste sistema é que pode ser utilizado em qualquer Instituição
e pode ser adaptado às diferentes necessidades alterando apenas os algoritmos ou
os critérios considerados. Esta Dissertação descreve algumas melhorias implementadas
no sistema existente, bem como algumas funcionalidades novas ao nível dos
algoritmos disponíveis.
As principais contribuições para o sistema são as seguintes: detecção de óculos de
sol, detecção de chapéus e análise de background. Para as duas primeiras, foi necessário
criar uma nova base de dados e rotulá-la para treinar, validar e testar uma
rede de aprendizagem profunda por transferência, utilizada para detectar os óculos
de sol e chapéus. Além disso, foram feitos vários testes variando os parâmetros
da rede e usando algumas técnicas de aprendizagem máquina e pré-processamento
sobre as imagens de entrada. Por fim, a análise do fundo consiste na implementação
e teste de 2 algoritmos existentes na literatura, um de baixo nível e outro de
aprendizagem profunda.
Globalmente, os resultados obtidos na melhoria dos algoritmos existentes, bem
como o desempenho dos novos módulos de processamneto de imagem, permitiram
criar um sistema de atualização de fotos do perfil mais robusto (melhoria
dos algoritmos da versão de produção) e versátil (adição de novos algoritmos ao
sistema).Mestrado em Engenharia Eletrónica e Telecomunicaçõe
New Waves of IoT Technologies Research – Transcending Intelligence and Senses at the Edge to Create Multi Experience Environments
The next wave of Internet of Things (IoT) and Industrial Internet of Things (IIoT) brings new technological developments that incorporate radical advances in Artificial Intelligence (AI), edge computing processing, new sensing capabilities, more security protection and autonomous functions accelerating progress towards the ability for IoT systems to self-develop, self-maintain and self-optimise. The emergence of hyper autonomous IoT applications with enhanced sensing, distributed intelligence, edge processing and connectivity, combined with human augmentation, has the potential to power the transformation and optimisation of industrial sectors and to change the innovation landscape. This chapter is reviewing the most recent advances in the next wave of the IoT by looking not only at the technology enabling the IoT but also at the platforms and smart data aspects that will bring intelligence, sustainability, dependability, autonomy, and will support human-centric solutions.acceptedVersio
A Distributed Audit Trail for the Internet of Things
Sharing Internet of Things (IoT) data over open-data platforms and digital data
marketplaces can reduce infrastructure investments, improve sustainability by
reducing the required resources, and foster innovation. However, due to the
inability to audit the authenticity, integrity, and quality of IoT data, third-party
data consumers cannot assess the trustworthiness of received data. Therefore,
it is challenging to use IoT data obtained from third parties for quality-relevant
applications. To overcome this limitation, the IoT data must be auditable. Distributed
Ledger Technology (DLT) is a promising approach for building auditable
systems. However, the existing solutions do not integrate authenticity,
integrity, data quality, and location into an all-encompassing auditable model
and only focus on specific parts of auditability.
This thesis aims to provide a distributed audit trail that makes the IoT auditable
and enables sharing of IoT data between multiple organizations for
quality relevant applications. Therefore, we designed and evaluated the Veritaa
framework. The Veritaa framework comprises the Graph of Trust (GoT) as
distributed audit trail and a DLT to immutably store the transactions that build
the GoT. The contributions of this thesis are summarized as follows. First, we
designed and evaluated the GoT a DLT-based Distributed Public Key Infrastructure
(DPKI) with a signature store. Second, we designed a Distributed
Calibration Certificate Infrastructure (DCCI) based on the GoT, which makes
quality-relevant maintenance information of IoT devices auditable. Third, we
designed an Auditable Positioning System (APS) to make positions in the IoT
auditable. Finally, we designed an Location Verification System (LVS) to verify
location claims and prevent physical layer attacks against the APS. All these
components are integrated into the GoT and build the distributed audit trail.
We implemented a real-world testbed to evaluate the proposed distributed audit
trail. This testbed comprises several custom-built IoT devices connectable
over Long Range Wide Area Network (LoRaWAN) or Long-Term Evolution
Category M1 (LTE Cat M1), and a Bluetooth Low Energy (BLE)-based Angle
of Arrival (AoA) positioning system. All these low-power devices can manage
their identity and secure their data on the distributed audit trail using the IoT
client of the Veritaa framework. The experiments suggest that a distributed
audit trail is feasible and secure, and the low-power IoT devices are capable
of performing the required cryptographic functions. Furthermore, the energy
overhead introduced by making the IoT auditable is limited and reasonable
for quality-relevant applications
Survey on 6G Frontiers: Trends, Applications, Requirements, Technologies and Future Research
Emerging applications such as Internet of Everything, Holographic Telepresence, collaborative robots, and space and deep-sea tourism are already highlighting the limitations of existing fifth-generation (5G) mobile networks. These limitations are in terms of data-rate, latency, reliability, availability, processing, connection density and global coverage, spanning over ground, underwater and space. The sixth-generation (6G) of mobile networks are expected to burgeon in the coming decade to address these limitations. The development of 6G vision, applications, technologies and standards has already become a popular research theme in academia and the industry. In this paper, we provide a comprehensive survey of the current developments towards 6G. We highlight the societal and technological trends that initiate the drive towards 6G. Emerging applications to realize the demands raised by 6G driving trends are discussed subsequently. We also elaborate the requirements that are necessary to realize the 6G applications. Then we present the key enabling technologies in detail. We also outline current research projects and activities including standardization efforts towards the development of 6G. Finally, we summarize lessons learned from state-of-the-art research and discuss technical challenges that would shed a new light on future research directions towards 6G
Control layer security: a new security paradigm for cooperative autonomous systems
Autonomous systems often cooperate to ensure safe navigation. Embedded within the centralised or distributed coordination mechanisms are a set of observations, unobservable states, and control variables. Security of data transfer between autonomous systems is crucial for safety, and both cryptography and physical layer security methods have been used to secure communication surfaces - each with its drawbacks and dependencies. Here, we show for the first time a new wireless Control Layer Security (CLS) mechanism. CLS exploits mutual physical states between cooperative autonomous systems to generate cipher keys. These mutual states are chosen to be observable to legitimate users and not sufficient to eavesdroppers, thereby enhancing the resulting secure capacity. The CLS cipher keys can encrypt data without key exchange or a common key pool, and offers very low information leakage. As such the security of digital data channels is now dependent on physical state estimation rather than wireless channel estimation. This protects the estimation process from wireless jamming and channel entropy dependency. We review for first time what kind of signal processing techniques are used for hidden state estimation and key generation, and the performance of CLS in different case studies.Engineering and Physical Sciences Research Council (EPSRC): EP/V026763/
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