Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by CSE

2020

The Impact of Olfactory and Wind Stimuli on 360 Videos Using Head-mounted Displays

Authors
Narciso, D; Melo, M; Vasconcelos Raposo, J; Bessa, M;

Publication
ACM TRANSACTIONS ON APPLIED PERCEPTION

Abstract
Consuming 360 audiovisual content using a Head-Mounted Display (HMD) has become a standard feature for Immersive Virtual Reality (IVR). However, most applications rely only on visual and auditory feedback whereas other senses are often disregarded. The main goal of this work was to study the effect of tactile and olfactory stimuli on participants' sense of presence and cybersickness while watching a 360 video using an HMD-based IVR setup. An experiment with 48 participants and three experimental conditions (360 video, 360 video with olfactory stimulus, and 360 video with tactile stimulus) was performed. Presence and cybersickness were reported via post-test questionnaires. Statistical analysis showed a significant difference in presence between the control and the olfactory conditions. From the control to the tactile condition, mean values were higher but failed to show statistical significance. Thus, results suggest that adding an olfactory stimulus increases presence significantly while the addition of a tactile stimulus only shows a positive effect. Regarding cybersickness, no significant differences were found across conditions. We conclude that an olfactory stimulus contributes to higher presence and that a tactile stimulus, delivered in the form of cutaneous perception of wind, has no influence in presence. We further conclude that multisensory cues do not affect cybersickness.

2020

MONITORING OF OLIVE TREES TEMPERATURES UNDER DIFFERENT IRRIGATION STRATEGIES BY UAV THERMAL INFRARED IMAGERY

Authors
Marques, P; Padua, L; Brito, T; Sousa, JJ; Fernandes Silva, A;

Publication
IGARSS 2020 - 2020 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM

Abstract
With the continuous escalation of global warming and consequent water scarcity, techniques to optimize water use of irrigation in agriculture are needed. Thus, deficit irrigation strategies (DI) can be used for a sustainable water usage. However, it is necessary to recursively monitor plant response under DI to ensure their productivity and prevent from severe water stress. The goal of this study is to assesscanopy and soil surface temperatures of olive trees under different irrigation strategies, through thermal infrared images obtained by Unmanned Aerial Vehicle (UAV). The temperatures from the different irrigation strategies were analysed with three approaches using the difference between canopy and air temperatures (Tc-Ta). The use of UAV-based thermal infrared imagery has proven to be extremely useful to the estimation of olive canopy and soil surface temperatures, which allow to discriminate different irrigation treatments.

2020

ArchOnto, a CIDOC-CRM-Based Linked Data Model for the Portuguese Archives

Authors
Koch, I; Ribeiro, C; Lopes, CT;

Publication
Digital Libraries for Open Knowledge - 24th International Conference on Theory and Practice of Digital Libraries, TPDL 2020, Lyon, France, August 25-27, 2020, Proceedings

Abstract
Archives are faced with great challenges due to the vast amounts of data they have to curate. New data models are required, and work is underway. The International Council on Archives is creating the RiC-CM (Records in Context), and there is a long line of work in museums with the CIDOC-CRM (CIDOC Conceptual Reference Model). Both models are based on ontologies to represent cultural heritage data and link them to other information. The Portuguese National Archives hold a collection with over 3.5 million metadata records, described with the ISAD(G) standard. The archives are designing a new linked data model and a technological platform with applications for archive contributors, archivists, and the public. The current work extends CIDOC-CRM into ArchOnto, an ontology-based model for archives. The model defines the relevant archival entities and properties and will be used to migrate existing records. ArchOnto accommodates the existing ISAD(G) information and takes into account its implementation with current technologies. The model is evaluated with records from representative fonds. After the test on these samples, the model is ready to be populated with the semi-automatic transformation of the ISAD records. The evaluation of the model and the population strategies will proceed with experiments involving professional and lay users. © 2020, Springer Nature Switzerland AG.

2020

Challenges Implementing the SimProgramming Approach in Online Software Engineering Education for Promoting Self and Co-regulation of Learning

Authors
Pedrosa, D; Morgado, L; Cravino, J; Fontes, MM; Castelhano, M; Machado, C; Curado, E;

Publication
PROCEEDINGS OF 2020 6TH INTERNATIONAL CONFERENCE OF THE IMMERSIVE LEARNING RESEARCH NETWORK (ILRN 2020)

Abstract
High academic failure rates in computer programming are significant transitioning from initial to advanced stages. In online higher education, challenges are greater since students' autonomy requires greater skills for self-regulation and co-regulation of learning. The SimProgramming approach develops these skills and is being adapted to e-learning for this transitioning phase. In this paper, we describe the dynamics and outcomes of student participation and task development in a first iteration of the adapted e-SimProgramming approach, which took place during a 2nd year-2nd semester course for the Informatics Engineering program at Universidade Aberta in the 2018/2019 academic year. We identified pedagogical and technical challenges, requiring changes for subsequent attempts of adopting SimProgramming for online education contexts: target audience and teaching context aspects; self and co-regulation of learning dimensions of e-learning courses; pedagogical design recommendations; and requirements for software tools for learning management.

2020

Evaluating the Accuracy of Password Strength Meters using Off-The-Shelf Guessing Attacks

Authors
Pereira, D; Ferreira, JF; Mendes, A;

Publication
2020 IEEE International Symposium on Software Reliability Engineering Workshops, ISSRE Workshops, Coimbra, Portugal, October 12-15, 2020

Abstract
In this paper we measure the accuracy of password strength meters (PSMs) using password guessing resistance against off-the-shelf guessing attacks. We consider 13 PSMs, 5 different attack tools, and a random selection of 60,000 passwords extracted from three different datasets of real-world password leaks. Our results show that a significant percentage of passwords classified as strong were cracked, thus suggesting that current password strength estimation methods can be improved. © 2020 IEEE.

2020

Joint event extraction along shortest dependency paths using graph convolutional networks

Authors
Balali, A; Asadpour, M; Campos, R; Jatowt, A;

Publication
KNOWLEDGE-BASED SYSTEMS

Abstract
Event extraction (EE) is one of the core information extraction tasks, whose purpose is to automatically identify and extract information about incidents and their actors from texts. This may be beneficial to several domains such as knowledge base construction, question answering and summarization tasks, to name a few. The problem of extracting event information from texts is longstanding and usually relies on elaborately designed lexical and syntactic features, which, however, take a large amount of human effort and lack generalization. More recently, deep neural network approaches have been adopted as a means to learn underlying features automatically. However, existing networks do not make full use of syntactic features, which play a fundamental role in capturing very long-range dependencies. Also, most approaches extract each argument of an event separately without considering associations between arguments which ultimately leads to low efficiency, especially in sentences with multiple events. To address the above-referred problems, we propose a novel joint event extraction framework that aims to extract multiple event triggers and arguments simultaneously by introducing shortest dependency path in the dependency graph. We do this by eliminating irrelevant words in the sentence, thus capturing long-range dependencies. Also, an attention-based graph convolutional network is proposed, to carry syntactically related information along the shortest paths between argument candidates that captures and aggregates the latent associations between arguments; a problem that has been overlooked by most of the literature. Our results show a substantial improvement over state-of-the-art methods on two datasets, namely ACE 2005 and TAC KBP 2015.

  • 83
  • 220