CIIC - Publicações em Atas de Conferências com Peer Review
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- 3D PARTICLE SYSTEMS FOR AUDIO APPLICATIONSPublication . Fonseca, NunoAlthough particle systems are well know for their use in computer graphics, their application in sound is very rare or almost non-existent. This paper presents a conceptual model for the use of particle systems in audio applications, using a full rendering system with virtual microphones: several virtual particles are spread over a virtual 3D space, where each particle reproduces one of the available audio streams (or a modified version), and the overall sound is captured by virtual microphones. Such system can be used on several audio-related areas like sound design, 3D mixing, reverb/impulse response design, granular synthesis, audio up-mixing, and impulse response up-mixing.
- Soluções SIEM open source: um estudo comparativoPublication . Vazão, Ana; Santos, Leonel; Piedade, Maria Beatriz; Rabadão, CarlosOs ataques informáticos estão a aumentar de complexidade e de número de ocorrências, tornando primordial implementar ferramentas como o Security Information and Event Management (SIEM) para mitigar os riscos, uma vez que as Organizações dependem cada vez mais dos sistemas informáticos para o desenvolvimento das suas atividades. O presente trabalho compara várias soluções SIEM open source, recorrendo à pesquisa bibliográfica e à implementação de vários cenários de testes, com o objetivo de criar um protótipo e de efetuar a avaliação do mesmo em contexto de produção. A solução escolhida vai ter de ter em consideração as exigências legais do Regulamento Geral de Proteção de Dados, como é o caso da anonimização e da pseudoanonimização dos dados sensíveis, o tempo de retenção dos logs e a sua encriptação.
- CoAP Flow Signatures for the Internet of ThingsPublication . Canuto, Luis; Santos, Leonel; Vieira, Leandro; Goncalves, Ramiro; Rabadão, CarlosThe development of technology brought an exponential evolution of IoT networks, and with a number of different devices connected to the Internet, meaning, more IP addresses, traffic and devices susceptible to attacks. These types of networks are characterized by their interoperability and low resources, making it a complex ecosystem and making it difficult to implement management and monitoring measures, leading to a lack of security. Considering the impact that IoT networks have on the market, their protection is essential and, is now one of the themes in constant evolution. With the focus on security, this work aims to characterize a CoAP and CoAPS signatures, through the analysis of a flow in a test scenario and recognize the types of messages of the signature and what is their impact on the network and later creating rules that could help an IDS, in order to save resources and time. When analyzing the flows, it was concluded that it is possible to identify some characteristics of a signature, such as identifying Confirmable and Non-Confirmable messages.
- Coding Tree Depth Estimation for Complexity Reduction of HEVCPublication . Correa, G.; Assunção, P.; Agostini, L.; Cruz, L. A. D. S.The emerging HEVC standard introduces a number of tools which increase compression efficiency in comparison to its predecessors at the cost of greater computational complexity. This paper proposes a complexity control method for HEVC encoders based on dynamic adjustment of the newly proposed coding tree structures. The method improves a previous solution by adopting a strategy that takes into consideration both spatial and temporal correlation in order to decide the maximum coding tree depth allowed for each coding tree block. Complexity control capability is increased in comparison to a previous work, while compression losses are decreased by 70%. Experimental results show that the encoder computational complexity can be downscaled to 60% with an average bit rate increase around 1.3% and a PSNR decrease under 0.07 dB.
- MQTT Flow Signatures for the Internet of ThingsPublication . Leal, Roberto; Santos, Leonel; Vieira, Leandro; Gonçalves, Ramiro; Rabadão, CarlosThe number of IoT devices and the volume of network traffic has grown continuously during the past years. IoT devices are smart devices designed with simple functions in mind, like collecting the temperature or opening a door. However, IoT devices lack a good security layer due to lack of resources: small memory, processor and/or battery. Consequently, new potential attacks and security problems have arisen. In order to detect and mitigate these security problems Intrusion Detection Systems (IDS) can be used, However, abnormal traffic must be distinguished from normal IoT patterns. In this article, a study was done on characterization of traffic signatures of two typical IoT application protocols - MQTT and MQTTS - with the objective of generating and collecting IP flows of said traffic. An IoT application scenario was simulated and using the traffic collected, an analysis of MQTT and MQTTS flows were elaborated to identify flow-based signatures that could be used to identify the network traffic of IoT application protocols.
- inGuide – Interactive GuidePublication . Batista, Filipe André Gomes; Rodrigues, Nuno; Gonçalves, AlexandrinoThis paper describes the inGuide - Interactive Guide application, a context-aware tourist guide that is presently available to Android smartphones. This application takes advantage of technologies such as Augmented Reality and geolocation in order to provide contextual information in a simple and interactive way. inGuide is a modular application which provides a package management system avoiding the need for a different version of the application for each city. Simultaneously it also surpasses one of the major hurdles related with mobile tourist applications, which is assuming always-on data connection and high speed network access.
- Using text mining to diagnose and classify epilepsy in childrenPublication . Luis Pereira; Rijo, Rui; Silva, Catarina; Agostinho, MargaridaEpilepsy diagnosis can be an extremely complex process, demanding considerable time and effort from physicians and healthcare infrastructures. Physicians need to classify each specific type of epilepsy based on different data, e.g., types of seizures, events and exams' results. This work presents a text mining approach to support medical decisions relating to epilepsy diagnosis and classification in children. We propose a text mining process that, using patient medical records, applies ontologies and named entities recognition as preprocessing steps, then applying K-Nearest Neighbors as a white-box lazy method to classify each instance. Results on real medical records suggest that the proposed framework shows good performance and clear interpretations, albeit the reduced volume of available training data.
- Os Desafios Web no Processo Formativo - O Caso de Estudo da humansoftPublication . Sousa, Mayelson de; Gonçalves, AlexandrinoA constante evolução das tecnologias web tem originado o aparecimento de plataformas que facilitam a gestão das tarefas dos utilizadores nos dias de hoje. No sentido de maximizar a satisfação do cliente e disporem de soluções de acordo com os padrões de atuais do mercado, as empresas devem adaptar os seus produtos, com particular enfoque nas soluções web-based, com vista a potenciar a usabilidade e a fluidez do seu uso. Neste sentido, este artigo apresenta um caso de estudo real, de desenvolvimento web na empresa humansoft, onde foram desenvolvidos diversos módulos relativos aos dois principais produtos da empresa, o humantrain, que é um sistema de gestão do processo formativo, e o humanportal, que é uma aplicação web que permite a interoperabilidade entre o humantrain e a web. Ambas as aplicações permitem às entidades formadoras e/ou empresas rentabilizarem a gestão dos seus recursos tanto ao nível pedagógico como financeiros.
- Performance analysis of AES encryption operation modes for IoT devicesPublication . Serra, Luís Filipe Dias; Gonçalves, Pedro Gonçalo Baptista; Frazão, Luís Alexandre Lopes; Antunes, Mário João GonçalvesDaily activities have been increasingly supported by intelligent devices and applications. Smart devices are constantly communicating through the Internet of Things (IoT) networks, either by sending collected data and notifying the actions taken or by receiving instructions for actions to be taken. Most of this communication requires the confidentiality of data through the usage of encryption algorithms, being the Advanced Encryption Standard (AES) algorithm one of the most used. However, how do the operation modes of AES algorithm perform in a resource-constraint device? This paper aims to evaluate the impact on the time to encrypt and decrypt different sized messages in IoT devices when using each one of the five AES modes of operation and the three key sizes defined. The test scenario was implemented using two programming languages, running on a Raspberry Pi device. The results achieved infers that Python was quicker and had a more homogeneous result set than JavaScript implementation in most AES operation modes. These results help to understand the trade-off between IoT devices' security needs and delays in communication caused by the selection of the AES algorithm operation mode.
- An end-to-end cryptography based real-time chatPublication . Melo, Tiezer; Barros, António; Antunes, Mário; Frazão, LuísConfidentiality protects users' data from digital eavesdroppers when traveling through the Internet. Confidentiality is complex and costly, especially on applications that involve communication and data exchange between multiple users. Cryptography has been the most used medium to achieve confidentiality, being the greatest challenge the sharing of a secret key to a group of people in a safe and effective way. This paper presents a chat application that implements an innovative way of sending messages with end-to-end encryption, in real-time, with a dynamic key store, and without the existence of data persistence. The application stands out from the others by the fact that it innovates the way the keys are shared with multiple users.