O uso de códigos QR nas Bibliotecas: a perspetiva do utilizador

O uso das tecnologias sem fios e de telemóveis tem vindo a aumentar substancialmente nos últimos anos. Vários estudos realizados nos Estados Unidos e no Canadá mostram que o número de adultos que possuiu telemóvel é elevado, com valores entre os 78 a 85%, dos quais 33 a 45% são smartphones. Hoje em dia, os telemóveis já não são apenas uma forma de falar com alguém e passaram a ser um meio para obter informação de forma rápida. Este facto fez com que se verificasse um acentuado desenvolvimento de tecnologias de suporte para estes dispositivos. Objetivo do estudo: avaliar o impacto da introdução dos Códigos QR na Biblioteca da Escola Superior de Tecnologia da Saúde de Lisboa (ESTeSL), quer a nível do serviço quer na perspetiva do utilizador.

Como usar a tecnologia móvel para promover o acesso aberto: o caso da Biblioteca da ESTeSL

O que são os códigos QR? São códigos de barras bidimensionais que permitem codificar e descodificar informação de forma quase imediata, através de um dispositivo móvel com câmara e com um software de leitura instalado. Objetivo do estudo: Desenvolver novos serviços para o crescente número de leitores que recorrem a dispositivos móveis. Porquê os códigos QR na ESTeSL? Promover os recursos em acesso aberto; facilitar o acesso a esses recursos; captar uma nova geração de utilizadores.

Improving Remote Voting Security with Code Voting

One of the major problems that prevents the spread of elections with the possibility of remote voting over electronic networks, also called Internet Voting, is the use of unreliable client platforms, such as the voter's computer and the Internet infrastructure connecting it to the election server. A computer connected to the Internet is exposed to viruses, worms, Trojans, spyware, malware and other threats that can compromise the election's integrity. For instance, it is possible to write a virus that changes the voter's vote to a predetermined vote on election's day. Another possible attack is the creation of a fake election web site where the voter uses a malicious vote program on the web site that manipulates the voter's vote (phishing/pharming attack). Such attacks may not disturb the election protocol, therefore can remain undetected in the eyes of the election auditors. We propose the use of Code Voting to overcome insecurity of the client platform. Code Voting consists in creating a secure communication channel to communicate the voter's vote between the voter and a trusted component attached to the voter's computer. Consequently, no one controlling the voter's computer can change the his/her's vote. The trusted component can then process the vote according to a cryptographic voting protocol to enable cryptographic verification at the server's side.

Design and performance of a novel low-density parity-check code for distributed video coding

Low-density parity-check (LDPC) codes are nowadays one of the hottest topics in coding theory, notably due to their advantages in terms of bit error rate performance and low complexity. In order to exploit the potential of the Wyner-Ziv coding paradigm, practical distributed video coding (DVC) schemes should use powerful error correcting codes with near-capacity performance. In this paper, new ways to design LDPC codes for the DVC paradigm are proposed and studied. The new LDPC solutions rely on merging parity-check nodes, which corresponds to reduce the number of rows in the parity-check matrix. This allows to change gracefully the compression ratio of the source (DCT coefficient bitplane) according to the correlation between the original and the side information. The proposed LDPC codes reach a good performance for a wide range of source correlations and achieve a better RD performance when compared to the popular turbo codes.