Percorrer por autor "Costa, Paulo"
A mostrar 1 - 10 de 12
Resultados por página
Opções de ordenação
- Correction to: A review of assistive spatial orientation and navigation technologies for the visually impairedPublication . Fernandes, Hugo; Costa, Paulo; Filipe, Vitor; Paredes, Hugo; Barroso, JoãoThe fourth author name was missed in the original publication. The correct list of authors should read as “Hugo Fernandes, Paulo Costa, Vitor Filipe, Hugo Paredes, João Barroso”. It has been corrected in this erratum. The original article has been updated.
- Fiducials Marks Detection to Assist Visually Impaired People NavigationPublication . Costa, Paulo; Fernandes, Hugo; Vasconcelos, Veronica; Coelho, Paulo; Barroso, Joao; Hadjileontiadis, LeontiosAssistive technology enables people to achieve independence in the accomplishment of their daily tasks and enhance their quality of life. Visual information is the basis for most navigational tasks, so visually impaired individuals are at disadvantage due to the lack of information or given unsufficient information about their surrounding environment. With the recent advances in inclusive technology it is possible to extend the support given to people with visual disabilities during their mobility. In this context we propose and describe the SmartVision project, whose global objective is to assist visually impaired people in their navigation through unknown indoor and outdoor environments. This paper is focused mainly on the Computer Vision module of the SmartVision prototype, were we propose a new algorithm to recognise fiducials marks suitably placed on sidewalks, revealing to be a promising solution.
- Integrating Computer Vision Object Recognition with Location Based Services for the BlindPublication . Fernandes, Hugo; Costa, Paulo; Paredes, Hugo; Filipe, Vítor; Barroso, JoãoThe task of moving from one place to another is a difficult challenge that involves obstacle avoidance, staying on street walks, finding doors, knowing the current location and keeping on track through the desired path. Nowadays, navigation systems are widely used to find the correct path, or the quickest, between two places. While assistive technology has contributed to the improvement of the quality of life of people with disabilities, people with visual impairment still face enormous limitations in terms of their mobility. In recent years, several approaches have been made to create systems that allow seamless tracking and navigation both in indoor and outdoor environments. However there is still an enormous lack of availability of information that can be used to assist the navigation of users with visual impairments as well as a lack of sufficient precision in terms of the estimation of the user's location. Blavigator is a navigation system designed to help users with visual impairments. In a known location, the use of object recognition algorithms can provide contextual feedback to the user and even serve as a validator to the positioning module and geographic information system of a navigation system for the visually impaired. This paper proposes a method where the use of computer vision algorithms validate the outputs of the positioning system of the Blavigator prototype.
- IoT in Greenhouse Supported by Climate Conditions Management PlatformPublication . Galvão, João; Neves, Filipe; Vieira, João; Rafael Simões; Ribeiro, Vânia; Costa, PauloThe system called iMeteo4all is a management platform for several physical variables, inherent to the control and management of climatic conditions inside structures, for the intensive production of plants called greenhouses and to be one contribution for agriculture 4.0. The objective of this work was to design and develop software for monitoring and managing the quality of the internal environment, through successive data collection/readings provided by a network of sensors and process automation for more efficient and sustainable agriculture. Different case studies of greenhouses whose production technologies are distinct, such as aquaponics and soil technologies were considered, in these controlled environment structures to produce plants (edible and non-edible). This platform requires an Internet address to perform the interface among a tablet, a cell phone, a computer and communication systems between a net of IoT (Internet of Things) sensors, which collect climatic variables inherent to growth and connected to several MCUs (Micro Controller Unit). Subsequently, managers and employees will be able to view and interact in real time, making more accurate decisions, depending on the climatic variations inside the greenhouse, increasing efficiency in several areas in greenhouses. It is possible to access the history of each sensor and configure automations according to the collected data. Access to data from this solution is secure through an SSL (Secure Sockets Layer) certificate applied to the public https address. If hardware failures exist, the system is prepared to be restored through regular backups in the cloud and internally, providing users with confidence and robustness in the constant use of this platform.
- Landmarks Detection to Assist the Navigation of Visually Impaired PeoplePublication . Costa, Paulo; Fernandes, Hugo; Vasconcelos, Verónica; Coelho, Paulo; Barroso, João; Hadjileontiadis, LeontiosAssistive technology enables people to achieve independence in the accomplishment of their daily tasks and enhance their quality of life. Visual information is the basis for most navigational tasks, so visually impaired individuals are at disadvantage due to the lack of information or given insufficient information about their surrounding environment. With the recent advances in inclusive technology it is possible to extend the support given to people with visual disabilities during their mobility. In this context we propose a new algorithm to recognize landmarks suitably placed on sidewalks. The proposed algorithm uses a combination of Peano-Hilbert Space Filling Curves for dimension reduction of image data and Ensemble Empirical Mode Decomposition (EEMD) to pre-process the image, resulting on a fast and efficient recognition method and revealing a promising solution.
- Lipid composition and nutritional quality of intramuscular fat in Charneca-PDO beefPublication . Pestana, José M; Costa, Ana S. H.; Alfaia, Cristina M.; Costa, Paulo; Martins, Susana V.; Alves, Susana P.; Bessa, Rui J. B.; Prates, José A. M.This paper characterizes the intramuscular fat from longissimus lumborum (LL, relatively red) and semitendinous (ST, relatively white) muscles of Charneca beef from young bulls reared according to the protected designation of origin (PDO) specifications. The content of total lipids, total cholesterol, α-tocopherol and β-carotene, as well as the fatty acid composition, including the isomeric distribution of conjugated linoleic acid (CLA), was assessed. Charneca young bulls (n = 10) were raised on a semi-extensive production system, in which animals fed pasture plus concentrate during 15 months. The ST muscle was leaner and had higher percentages of PUFA, in contrast to the LL muscle, which presented higher percentages of SFA and MUFA. Thus, the ST muscle had a higher PUFA/SFA ratio than the LL muscle, although the ratio values of both muscles were inside the recommended figures for the human diet. In contrast, the contents of CLA isomers, total cholesterol, α-tocopherol and β-carotene, as well as the n-6/n-3 ratio, were not influenced by muscle type, thus suggesting no carcass variation for these compounds. In both muscles, the n-6/n-3 ratios were slightly above the dietary guideline for human diet, and the contents of α-tocopherol were very high, indicating a good lipid stability of Charneca-PDO beef. Overall, the results suggest that intramuscular fat of Charneca-PDO beef has good human health-related parameters, with small carcass variation, since the PUFA/SFA and n-6/n-3 ratio values are inside or very close to the recommended figures for the human diet, and the content of α-tocopherol is very high.
- Location based Services for the Blind Supported by RFID TechnologyPublication . Fernandes, H.; Filipe, Vitor; Costa, Paulo; Barroso, JoãoNowadays, navigation systems are widely used to find the correct path, or the quickest, between two places. These systems use the Global Positioning System (GPS) and only work well in outdoor environment since GPS signals cannot easily penetrate and/or are greatly degraded inside of buildings. Several technologies have been proposed to make navigation inside of buildings possible. One such technology is Radio-Frequency Identification (RFID). In the case of outside environments, some hybrid systems have been proposed that use GPS as main information source and RFID for corrections and location error minimization. In this article we propose a navigation system that uses RFID as the main technology to guide people with visual impairment in unfamiliar environments, both indoor and outdoor, complementing the traditional white cane and providing information about the user's geographical context.
- Obstacle detection and avoidance module for the blindPublication . Costa, Paulo; Fernandes, Hugo; Barroso, João; Paredes, Hugo; Hadjileontiadis, Leontios J.; CostaAssistive technology enables people to achieve independence when performing daily tasks and it enhances their overall quality of life. Visual information is the basis for most navigational tasks, so visually impaired individuals are at disadvantage due to the lack of sufficient information about their surrounding environment. With recent advances in inclusive technology it is possible to extend the support given to people with visual disabilities in terms of their mobility. In this context we present and describe a wearable system (Blavigator project), whose global objective is to assist visually impaired people in their navigation on indoor and outdoor environments. This paper is focused mainly on the Computer Vision module of the Blavigator prototype. We propose an object collision detection algorithm based on stereo vision. The proposed algorithm uses Peano-Hilbert Ensemble Empirical Mode Decomposition (PH-EEMD) for disparity image processing and a two layer disparity image segmentation to detect nearby objects. Using the adaptive ensemble empirical mode decomposition (EEMD) image analysis real time is not achieved, with PH-EEMD results on a fast implementation suitable for real time applications.
- Obstacle Detection using Stereo Imaging to Assist the Navigation of Visually Impaired PeoplePublication . Costa, Paulo; Fernandes, Hugo; Martins, Paulo; Barroso, João; Hadjileontiadis, Leontios J.Assistive technology enables people to achieve independence when performing daily tasks and it enhances their overall quality of life. Visual information is the basis for most navigational tasks, so visually impaired individuals are at disadvantage due to the lack of sufficient information about their surrounding environment. With recent advances in inclusive technology it is possible to extend the support given to people with visual disabilities in terms of their mobility. In this context we propose and describe the Blavigator project, whose global objective is to assist visually impaired people in their navigation on indoor and outdoor environments. This paper is focused mainly on the Computer Vision module of the Blavigator prototype. We propose an object collision detection algorithm based on disparity images. The proposed algorithm uses a 2D Ensemble Empirical Mode Decomposition image optimization algorithm and a two layer disparity image segmentation to detect nearby objects.
- Prototype to Increase Crosswalk Safety by Integrating Computer Vision with ITS-G5 TechnologiesPublication . Gaspar, Francisco; Guerreiro, Vitor; Loureiro, Paulo; Costa, Paulo; Mendes, Sílvio; Rabadão, CarlosHuman errors are probably the main cause of car accidents, and this type of vehicle is one of the most dangerous forms of transport for people. The danger comes from the fact that on public roads there are simultaneously different types of actors (drivers, pedestrians or cyclists) and many objects that change their position over time, making difficult to predict their immediate movements. The intelligent transport system (ITS-G5) standard specifies the European communication technologies and protocols to assist public road users, providing them with relevant information. The scientific community is developing ITS-G5 applications for various purposes, among which is the increasing of pedestrian safety. This paper describes the developed work to implement an ITS-G5 prototype that aims at the increasing of pedestrian and driver safety in the vicinity of a pedestrian crosswalk by sending ITS-G5 decentralized environmental notification messages (DENM) to the vehicles. These messages are analyzed, and if they are relevant, they are presented to the driver through a car’s onboard infotainment system. This alert allows the driver to take safety precautions to prevent accidents. The implemented prototype was tested in a controlled environment pedestrian crosswalk. The results showed the capacity of the prototype for detecting pedestrians, suitable message sending, the reception and processing on a vehicle onboard unit (OBU) module and its presentation on the car onboard infotainment system.