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Publications

2021

Performance Enhancement of a Neato XV-11 Laser Scanner Applied to Mobile Robot Localization: A Stochastic Modeling Approach

Authors
Gonçalves, J; Coelho, JP; Braz César, M; Costa, P;

Publication
CONTROLO 2020

Abstract
Laser scanners are widely used in mobile robotics localization systems but, despite the enormous potential of its use, their high price tag is a major drawback, mainly for hobbyist and educational robotics practitioners that usually have a reduced budget. The Neato XV-11 Laser Scanner is a very low cost alternative, when compared with the current available laser scanners, being this fact the main motivation for its use. The modeling of a hacked Neato XV-11 Laser Scanner allows to provide valuable information that can promote the development of better designs of robot localization systems based on this sensor. This paper presents, as an example, the performance enhancement of a Neato XV-11 Laser Scanner applied to mobile robot self-localization, being used as case study the Perfect Match Algorithm applied to the Robot@Factory competition. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021.

2021

SmoothMV: Seamless Content Adaptation through Head Tracking Analysis and View Prediction

Authors
da Costa, TS; Andrade, MT; Viana, P;

Publication
PROCEEDINGS OF THE 2021 INTERNATIONAL WORKSHOP ON IMMERSIVE MIXED AND VIRTUAL ENVIRONMENT SYSTEMS (MMVE '21)

Abstract
Multi-view has the potential to offer immersive viewing experiences to users, as an alternative to 360 degrees and Virtual Reality (VR) applications. In multi-view, a limited number of camera views are sent to the client and missing views are synthesised locally. Given the substantial complexity associated to view synthesis, considerable attention has been given to optimise the trade-off between bandwidth gains and computing resources, targeting smooth navigation and viewing quality. A still relatively unexplored field is the optimisation of the way navigation interactivity is achieved, i.e. how the user indicates to the system the selection of new viewpoints. In this article, we introduce SmoothMV, a multi-view system that uses a non-intrusive head tracking approach to enhance navigation and Quality of Experience (QoE) of the viewer. It relies on a novel Hot&Cold matrix concept to translate head positioning data into viewing angle selections. Streaming of selected views is done using MPEG-DASH, where a proposed extension to the standard descriptors enables to achieve consistent and flexible view identification.

2021

Emotion Identification in Movies through Facial Expression Recognition

Authors
Almeida, J; Vilaca, L; Teixeira, IN; Viana, P;

Publication
APPLIED SCIENCES-BASEL

Abstract
Understanding how acting bridges the emotional bond between spectators and films is essential to depict how humans interact with this rapidly growing digital medium. In recent decades, the research community made promising progress in developing facial expression recognition (FER) methods. However, no emphasis has been put in cinematographic content, which is complex by nature due to the visual techniques used to convey the desired emotions. Our work represents a step towards emotion identification in cinema through facial expressions' analysis. We presented a comprehensive overview of the most relevant datasets used for FER, highlighting problems caused by their heterogeneity and to the inexistence of a universal model of emotions. Built upon this understanding, we evaluated these datasets with a standard image classification models to analyze the feasibility of using facial expressions to determine the emotional charge of a film. To cope with the problem of lack of datasets for the scope under analysis, we demonstrated the feasibility of using a generic dataset for the training process and propose a new way to look at emotions by creating clusters of emotions based on the evidence obtained in the experiments.

2021

An ML-style Record Calculus with Extensible Records

Authors
Alves, S; Ramos, M;

Publication
Electronic Proceedings in Theoretical Computer Science, EPTCS

Abstract
In this work, we develop a polymorphic record calculus with extensible records. Extensible records are records that can have new fields added to them, or preexisting fields removed from them. We also develop a static type system for this calculus and a sound and complete type inference algorithm. Most ML-style polymorphic record calculi that support extensible records are based on row variables. We present an alternative construction based on the polymorphic record calculus developed by Ohori. Ohori based his polymorphic record calculus on the idea of kind restrictions. This allowed him to express polymorphic operations on records such as field selection and modification. With the addition of extensible types, we were able to extend Ohori’s original calculus with other powerful operations on records such as field addition and removal. © S. Alves & M. Ramos

2021

Improving Efficiency and Effectiveness in the Development of Customized Software Solutions: A Case Study in a Service-Oriented Company

Authors
Fernandes, M; Azevedo, A;

Publication
Proceedings of the International Conference on Industrial Engineering and Operations Management

Abstract
This paper presents the approach and results of an improvement project carried on by a company that provides business process outsourcing services based on customised software solutions. The critical objectives considered were to increase the efficiency and effectiveness of the processes involved in developing customised solutions. Thus, the focus of this research was to identify problems in current processes and practices and develop possible solutions to improve. The processes were mapped, the inefficiencies were identified, and suggestions for improvements were presented and analysed. It was concluded that the main problems with the project management and software development processes are related to the lack of visibility of the team load, lack of standardisation and inefficient management processes. These causes result in problems such as IT being unable to plan work and problems associated with quality that negatively influence the lead time of projects. Therefore, suggestions for improvement were formulated and prioritised to address each of these aspects. A more agile approach to software development and redesigning the processes for creating customised solutions were the solutions developed. There was also a need to develop the existing project management software changes to adapt it to these changes. © IEOM Society International.

2021

The Benefits of Virtual Reality Technology for Rehabilitation of Children with Autism: A Systematic Review

Authors
Silva R.; Duque D.; Melo M.; Moura J.M.;

Publication
ICGI 2021 - 2021 International Conference on Graphics and Interaction, Proceedings

Abstract
This paper presents a literature review of the importance of virtual technology for rehabilitation for people with ASD (Autism Spectrum Disorder). ASD is diagnosed as a neurological disability characterized by a range of physical and mental disorders and whose first symptoms appear during early childhood. People with autism deal with issues with social communication, behavior, and attention skills. As a sensitive disturbance, adapted technology allows to re-learn skills stimulating procedures about how to proceed, communicate or behave without difficulties in unexpected environments. The use of technology in educational contexts, home or at school, helps prevent and teach younger people with ASD. Considering different technologies as more appropriate methods, Virtual Reality (VR) applications and personalized environments provide better simulation and comfortable environments. As the main advantage of VR, complete immersion and interactive experience promotes constant learning for people with autism. This systematic review details the benefits of VR studies and compares the benefits of different interactive technologies according to the deficits of several individuals. The use of technology versus the traditional path on therapies helps obtain better and faster results over time. Finally, it explains how VR can be recognized as a tool to help develop cognitive, verbal and nonverbal skills and recognizes technology as a good ally to face fears or reactions by ASD people.

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