51 documents found, page 1 of 6
Recognition of human activity based on sparse data collected from smartphone se...
Figueiredo, João; Gordalina, Gonçalo; Frazão Correia, Pedro; Pires, Gabriel; Lopes de Oliveira, Luís Miguel; Martinho, Ricardo; Rijo, RuiThis paper proposes a method of human activity monitoring based on the regular use of sparse acceleration data and GPS positioning collected during smartphone daily utilization. The application addresses, in particular, the elderly population with regular activity patterns associated with daily routines. The approach is based on the clustering of acceleration and GPS data to characterize the user's pattern acti...
Recognition of human activity based on sparse data collected from smartphone se...
Gordalina, Goncalo; Correia, Pedro; Pires, Gabriel; Oliveira, Luis; Figueiredo, Maria João; Martinho, Ricardo; Rijo, Rui, Rui Pedro Charters LopesThis paper proposes a method of human activity monitoring based on the regular use of sparse acceleration data and GPS positioning collected during smartphone daily utilization. The application addresses, in particular, the elderly population with regular activity patterns associated with daily routines. The approach is based on the clustering of acceleration and GPS data to characterize the user’s pattern acti...
A Cardiac Rehabilitation Program Supported by mHealth Technology: The MOVIDA.er...
Silva, Emanuel; Rijo, Rui; Martinho, Ricardo; Assunção, Pedro; Seco, Alexandra; Fonseca-Pinto, RuiThe cardiac rehabilitation backdrop in Portugal is lacking much-needed improvements in order to better serve patients with different heart conditions. Although the beneficial results of cardiac rehabilitation are widely acknowledged, it is not being implemented in an optimal way, with few rehabilitation centers irregularly distributed throughout the country. In this context, the opportunity arose to develop a p...
Tracking human routines towards adaptive monitoring: the MOVIDA.domus platform
Gordalina, Gonçalo; Figueiredo, João; Martinho, Ricardo; Rijo, Rui; Correia, Pedro; Assunção, Pedro; Seco, Alexandra; Pires, Gabriel; Oliveira, LuísAccording to estimates by the World Health Organization, the average life expectancy will continue to rise. This indicator, being a measure of success in terms of healthcare, is not synonymous with quality of life and will increase healthcare costs. Associated with this problem are also the changes in terms of the organization of society, which has not been able to solve these constraints of functional limitati...
Retargeting UHD 4k Video for Smartphones
Kumar, Rohit; Navarro, António; Assunção, Pedro; Ferreira, LinoThis paper evaluates a new video-retargeting algorithm jointly with two others previously published in the literature. Four Ultra High Definition (UHD) 4K resolution video sequences were used for subjective assessment. Subjective testing results show that the proposed algorithm yields the best performance when UHD 4K video is retargeted to 1920 × 1080 resolution. The main application of these retargeting algori...
Optimal voice packet classification for enhanced VoIP over priority-enabled net...
Neves, Filipe; Soares, Salviano; Assunção, PedroThis paper proposes a method for optimal classification of voice packets to enhance the quality of voice communications over priority-enabled networks when poor transmission conditions occur. Either high or low priority is assigned to each packet according to the relevance of its payload (voice segment) for the voice intelligibility. Then, in case of constrained networking conditions, by discarding first the vo...
Retargeting 4K Video for Mobile Access Using Visual Attention and Temporal Stab...
Kumar, Rohit; Ferreira, Lino; Assunção, Pedro; Navarro, AntónioThis paper presents different methods of retargeting 4K resolution videos for the smaller resolutions of mobile devices. Several methods are investigated using image cropping based on visual attention maps with removal of temporal jitter. Visual comparison between video sequences obtained from the retargeting methods is presented and evaluated through subjective testing. Based on subjective scores, the proposed...
A method for automatic detection of rectangular regions of interest in arbitrar...
Martins-Ferreira, Nelson; Ferreira, Lino; Pascoal-Faria, Paula; Cruz, Luis A. da Silva; Assunção, Pedro; Alves, NunoThis paper presents a computational method to extract optimum rectangular Regions of Interest (RoI) in images with an associated saliency map. Although saliency maps provide an individual relevance measure for each pixel, to find the sub-image (i.e., rectangular region) that contains the set of the most relevant pixels requires an optimisation procedure to define the boundaries of the best RoI. This is achieved...
Evaluation of cutaneous microcirculation patterns by laser speckle imaging
Bento, L.; de Oliveira Pegado de Noronha E Távora, Luís Miguel; Assunção, Pedro; Faria, Sergio; Fonseca-Pinto, RuiAtherosclerosis is a chronic systemic process affecting distal circulation, a condition known as Peripheral Artery Disease (PAD). Epidemiological and clinical studies indicate a strong association between PAD and death due to cardiovascular diseases, thus the early detection of DAP by measuring perfusion levels of distal body regions is critical to prevent ischemic events. This work proposes a new methodology f...
Lossless coding of light field images based on minimum-rate predictors
Santos, João M.; Assunção, Pedro; Cruz, Luis A. da Silva; de Oliveira Pegado de Noronha E Távora, Luís Miguel; Fonseca-Pinto, Rui; Faria, SergioRecent developments in light field acquisition and computational photography are driving new research efforts on light field encoding methods, capable of exploiting the specific features of this type of visual data. This paper presents a research study of lossless light field image compression, using Minimum-Rate Predictors (MRP) and mainstream image and video encoders. The research is focused on three light fi...