2,492 research outputs found
Music Boundary Detection using Convolutional Neural Networks: A comparative analysis of combined input features
The analysis of the structure of musical pieces is a task that remains a
challenge for Artificial Intelligence, especially in the field of Deep
Learning. It requires prior identification of structural boundaries of the
music pieces. This structural boundary analysis has recently been studied with
unsupervised methods and \textit{end-to-end} techniques such as Convolutional
Neural Networks (CNN) using Mel-Scaled Log-magnitude Spectograms features
(MLS), Self-Similarity Matrices (SSM) or Self-Similarity Lag Matrices (SSLM) as
inputs and trained with human annotations. Several studies have been published
divided into unsupervised and \textit{end-to-end} methods in which
pre-processing is done in different ways, using different distance metrics and
audio characteristics, so a generalized pre-processing method to compute model
inputs is missing. The objective of this work is to establish a general method
of pre-processing these inputs by comparing the inputs calculated from
different pooling strategies, distance metrics and audio characteristics, also
taking into account the computing time to obtain them. We also establish the
most effective combination of inputs to be delivered to the CNN in order to
establish the most efficient way to extract the limits of the structure of the
music pieces. With an adequate combination of input matrices and pooling
strategies we obtain a measurement accuracy of 0.411 that outperforms the
current one obtained under the same conditions
Acoustic Scene Classification
This work was supported by the Centre for Digital Music Platform (grant EP/K009559/1) and a Leadership Fellowship
(EP/G007144/1) both from the United Kingdom Engineering and Physical Sciences Research Council
Real Time Fusion of Radioisotope Direction Estimation and Visual Object Tracking
Research into discovering prohibited nuclear material plays an integral role in providing security from terrorism. Although many diverse methods contribute to defense, there exists a capability gap in localizing moving sources. This thesis introduces a real time radioisotope tracking algorithm assisted by visual object tracking methods to fill the capability gap. The proposed algorithm can estimate carrier likelihood for objects in its field of view, and is designed to assist a pedestrian agent wearing a backpack detector. The complex, crowd-filled, urban environments where this algorithm must function combined with the size and weight limitations of a pedestrian system makes designing a functioning algorithm challenging.The contribution of this thesis is threefold. First, a generalized directional estimator is proposed. Second, two state-of-the-art visual object detection and visual object tracking methods are combined into a single tracking algorithm. Third, those outputs are fused to produce a real time radioisotope tracking algorithm. This algorithm is designed for use with the backpack detector built by the IDEAS for WIND research group. This setup takes advantage of recent advances in detector, camera, and computer technologies to meet the challenging physical limitations.The directional estimator operates via gradient boosting regression to predict radioisotope direction with a variance of 50 degrees when trained on a simple laboratory dataset. Under conditions similar to other state-of-the-art methods, the accuracy is comparable. YOLOv3 and SiamFC are chosen by evaluating advanced visual tracking methods in terms of speed and efficiency across multiple architectures, and in terms of accuracy on datasets like the Visual Object Tracking (VOT) Challenge and Common Objects in Context (COCO). The resultant tracking algorithm operates in real time. The outputs of direction estimation and visual tracking are fused using sequential Bayesian inference to predict carrier likelihood. Using lab trials evaluated by hand on visual and nuclear data, and a synthesized challenge dataset using visual data from the Boston Marathon attack, it can be observed that this prototype system advances the state-of-the-art towards localization of a moving source
Development of an R package to learn supervised classification techniques
This TFG aims to develop a custom R package for teaching supervised classification algorithms, starting
with the identification of requirements, including algorithms, data structures, and libraries. A strong
theoretical foundation is essential for effective package design. Documentation will explain each function’s
purpose, accompanied by necessary paperwork.
The package will include R scripts and data files in organized directories, complemented by a user
manual for easy installation and usage, even for beginners. Built entirely from scratch without external
dependencies, it’s optimized for accuracy and performance.
In conclusion, this TFG provides a roadmap for creating an R package to teach supervised classification
algorithms, benefiting researchers and practitioners dealing with real-world challenges.Grado en IngenierÃa Informátic
Detecção de anomalias na partilha de ficheiros em ambientes empresariais
File sharing is the activity of making archives (documents, videos, photos) available to other users. Enterprises use file sharing to make archives available to their employees or clients. The availability of these files can be done through an internal network, cloud service (external) or even Peer-to-Peer (P2P). Most of the time, the files within the file sharing service have sensitive
information that cannot be disclosed. Equifax data breach attack exploited a zero-day attack that allowed arbitrary code execution, leading to a huge data breach as over 143 million user information was presumed compromised. Ransomware is a type of malware that encrypts computer data (documents, media, ...) making it inaccessible to the user, demanding a ransom for the decryption of the data. This type of malware has been a serious threat to enterprises.
WannaCry and NotPetya are some examples of ransomware that had a huge impact on enterprises with big amounts of ransoms, for example WannaCry reached more than 142,361.51 em
resgates. Neste tabalho, propomos um sistema que consiga detectar anomalias na partilha de ficheiros, como o ransomware (WannaCry, NotPetya) e roubo de dados (violação de dados Equifax), bem como a sua propagação. A solução consiste na monitorização da rede da empresa, na criação de perfis para cada utilizador/máquina, num algoritmo de machine learning para análise dos dados e num mecanismo que bloqueie a máquina afetada no caso de se detectar uma anomalia.Mestrado em Engenharia de Computadores e Telemátic
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