José Manuel Fonseca

dblp:47/5777 · also José Fonseca 0001, José M. Fonseca 0001, José Manuel Matos Ribeiro da Fonseca, José R. Fonseca 0001 · DBLP profile ↗
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20ranked-venue papers
1as first author
6since 2021 · last 2025
0000-0001-7173-7374ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Applied, interdisciplinary, general and emerging computing · 11 · 6 since 2021Artificial intelligence and machine learning · 9 · 1 first-authorHuman-computer interaction and ubiquitous computing · 2Systems, architecture and hardware · 1 · 1 first-authorSoftware engineering, systems software and programming languages · 1
YearPublicationVenuePosition
2025 Forest Height Mapping With Multifrequency SAR in Mediterranean Forests
abstract
The importance of mapping the forest height (FH) is increasing due to the more frequent impacts of climate change in the society (wildfires, droughts, and extreme weather events). Remote Sensing is often used for mapping this variable; however, it usually relies in costly and extensive field or airborne campaigns. In addition, when using synthetic aperture radar (SAR), most approaches do not use freely available data. Considering this, in this work a model is proposed that resorts to Advanced Land Observing Satellite 2 (ALOS-2), Sentinel-1 (S1), and ancillary data. Airborne laser scanning (ALS) data are used for local calibration but, with the aim of developing a more scalable model, the latter is optimized to work with small calibration datasets (representative of just 25% of the study area to be mapped). With this purpose, the model combines a featuring generation and a features’ processing stage with a stacking regressor to produce estimates at the pixel level. Their impact was assessed, and an improvement of 8.11 and 2.01 pp in the relative root mean square error (rRMSE) was achieved by including the features’ generation and features’ processing stages, respectively. In addition, when the multifrequency dataset was used, the model achieved an rRMSE better than when using only a C-band dataset (S1) or only an L-band dataset (ALOS-2), respectively, by 4.21 and 3.05 pp. Finally, the model achieved an average${R} ^{2}$/rRMSE of 0.6240%/24.30% and 0.5901%/22.64% for the validation and test study areas, respectively. The proposed approach revealed to be effective on mapping the FH resorting to multifrequency SAR and small calibration datasets acquired by ALS.
João E. Pereira-Pires, Juan Guerra-Hernández, João M. N. Silva, José Manuel Fonseca, Raffaella Guida, André Mora
IEEE Trans. Geosci. Remote. Sens.4
2024 Forest Height Mapping Combining GEDI, ALOS-2, Sentinel-1/2, and Ancillary Data
abstract
The impacts of the climate change in the society make forest monitoring increasingly important. Consequently, there is a growing interest in mapping variables as the Forest Height (FH). The direct measurement of the FH through field campaigns is expensive and difficult to scale. Alternatively, Airborne Laser Scanning (ALS) campaigns can be used to map it, however they share the same disadvantages of the previous approach. Therefore, Remote Sensing (RS) data have been used for local and large-scale mapping of the FH. In this paper a Regression Methodology (RM) that combines GEDI, ALOS-2, Sentinel-1/2, and ancillary data is proposed for mapping the FH in Mediterranean forests. The proposed RM, tested for the 15 regions of interest, achieves a RMSE/rRMSE of 4.95m/33.93%, when evaluated with GEDI data, and 5.11m/41.70%, when evaluated with ALS data.
João E. Pereira-Pires, Juan Guerra-Hernández, João M. N. Silva, José Manuel Fonseca, Raffaella Guida, André Mora
IGARSS4
2023 Multispectral vs Synthetic Aperture Radar Data for Canopy Height Estimation
abstract
Canopy Height (CH) is an important variable in any forest inventory, not only by its own information, but also as a proxy variable to estimate other parameters as the above-ground biomass. The CH information can also be helpful to understand the climate change trends, for forest management, and in decision support systems related to wildfires. The growing availability of Remote Sensing observations acquired from different sensors, create an alternative for the CH mapping to field campaigns and Airborne Laser Scanning (ALS) missions. Here a comparison between using Multispectral and Synthetic Aperture Radar sensors for CH estimation is presented. Both used the same Regression Methodology, being achieved a R2/RMSE between 43.71%-72.85%/0.85-4.03m for Multispectral and 42.12%-62.62%/0.96m-4.49m for SAR, for a total of 17 regions of interest. It is concluded that Multispectral data revealed to be more suitable for the CH mapping.
João E. Pereira-Pires, João M. N. Silva, José Manuel Fonseca, Raffaella Guida, André Mora
IGARSS3
2023 Forest Height Estimation Using Multi-Frequency Sar and a Stacking Regression
abstract
The knowledge of the Forest Height (FH) is important for monitoring the forests, and it can be used as a proxy variable of other forest parameters as the aboveground biomass. It is also important for understanding the climate change and prepare the wildfire seasons. The most effective way to map the FH is through field campaigns or airborne laser scanning, but both are expensive and not scalable. Alternatively, spaceborne Synthetic Aperture Radar (SAR) data may be used. However, it often relies on the acquisition of large ground truth datasets. In this paper, a new Regression Methodology (RM) that makes use of SAR data and a Stacking Regressor that minimises the amount of data needed to map the FH of a region is presented. Tested on a total of 16 regions between Portugal and Spain, plus one in California, the RM achieved a R2between 42.12%-62.62%, and a RMSE between 0.96m-4.49m.
João E. Pereira-Pires, João M. N. Silva, José Manuel Fonseca, André Mora, Raffaella Guida
IGARSS3
2023 Using Sentinel-2 and Stacking Regressors for Forest Height Estimation
abstract
The climate change impacts can also be seen in the growing number of wildfires. Consequently, forest management and the updating of forest inventories become more important in the wildfires’ avoidance. Measuring the Forest Height (FH) is an important activity in forests monitoring, since the FH can serve as a proxy variable of other parameters, as the aboveground biomass. Normally, FH is mapped through field campaigns or airborne laser scanning missions. However, these approaches do not offer the scalability needed and they are expensive. Therefore, multispectral data from Remote Sensing can be used for producing regional maps of FH. Here it is proposed a regionally calibrated Regression Methodology that uses multispectral data from Sentinel-2 and a Stacking Regressor for mapping the FH in Mediterranean forests. For a total of 17 regions across Portugal, Spain, and California, a R2between 43.71% and 72.85% and a RMSE between 0.85m and 4.03m.
João E. Pereira-Pires, João M. N. Silva, André Mora, José Manuel Fonseca
IGARSS4
2021 Fuel Break Vegetation Monitoring with Sentinel-2 NDVI Robust to Phenology and Environmental Conditions
abstract
Wildfires are recurrent natural disasters in some regions of the globe, being Portugal one of these areas. The Portuguese Institute for Nature Conservation and Forests implemented a national fuel break (FB) network, with the goal of decreasing fire hazard. FBs are areas of reduced fuel load that slow down fire spread, creating firefighting opportunities. Its effectiveness relies on periodic treatments to maintain the fuel load in levels that can reduce the effects of wildfires. This paper proposes a methodology to assess the FB state, according to its fuel load, based on the analysis of the inter-annual variability of Sentinel-2 NDVI time series. Inter-annual comparison allows it to adapt to different regions. To assess the reliability of NDVI data to evaluate the FB state, a linear regression with the vegetation height acquired by the Global Ecosystem Dynamics Investigation (GEDI) mission was tested, achieving determination coefficients between 0.57 and 0.98.
João E. Pereira-Pires, Valentine Aubard, Rita Almeida Ribeiro, José Manuel Fonseca, João M. N. Silva, André Mora
IGARSS4
2019 Use of Particle Swarm Optimization in Terrain Classification based on UAV Downwash
abstract
Nowadays, the number of aerial unmanned vehicles (UAVs) is growing at a tremendous speed, as well as its technology. Therefore, it is essential to follow this growth with increasingly robust algorithms to be possible to exist cooperation between robots autonomously. One of the major events currently being developed in autonomous cooperation is relatively terrain classification where, this classification, is mainly important for emergency landings, mapping and decision making. This paper presents a robust computer vision system to sort terrain types using two main algorithms: Particle Swarm Optimization (PSO) and Gray-Level Co-Occurrence Matrix (GLCM). In addition to these two algorithms, a neural network was designed with the aim of increasing the probability of success of the proposed system. In order to evaluate this article, the system is validated using videos acquired onboard of a UAV with a RGB camera.
Iuliia Kim, João Pedro Matos-Carvalho, Ilya I. Viksnin, Luís Miguel Campos, José Manuel Fonseca, André Mora, Sergei Chuprov
CEC5
2018 UAV downwash dynamic texture features for terrain classification on autonomous navigation
abstract
The information generated by a computer vision system capable of labelling a land surface as water, vegetation, soil or other type, can be used for mapping and decision making.For example, an unmanned aerial vehicle (UAV) can use it to find a suitable landing position or to cooperate with other robots to navigate across an unknown region.Previous works on terrain classification from RGB images taken onboard of UAVs shown that only static pixel-based features were tested with a considerable classification error.This paper proposes a robust and efficient computer vision algorithm capable of classifying the terrain from RGB images with improved accuracy.The algorithm complement the static image features with dynamic texture patterns produced by UAVs rotors downwash effect (visible at lower altitudes) and machine learning methods to classify the underlying terrain.The system is validated using videos acquired onboard of a UAV.
João Pedro Matos-Carvalho, José Manuel Fonseca, André Mora
FedCSIS2
2018 SCIP: a single-cell image processor toolbox
abstract
Summary: Each cell is a phenotypically unique individual that is influenced by internal and external processes, operating in parallel. To characterize the dynamics of cellular processes one needs to observe many individual cells from multiple points of view and over time, so as to identify commonalities and variability. With this aim, we engineered a software, 'SCIP', to analyze multi-modal, multi-process, time-lapse microscopy morphological and functional images. SCIP is capable of automatic and/or manually corrected segmentation of cells and lineages, automatic alignment of different microscopy channels, as well as detect, count and characterize fluorescent spots (such as RNA tagged by MS2-GFP), nucleoids, Z rings, Min system, inclusion bodies, undefined structures, etc. The results can be exported into *mat files and all results can be jointly analyzed, to allow studying not only each feature and process individually, but also find potential relationships. While we exemplify its use on Escherichia coli, many of its functionalities are expected to be of use in analyzing other prokaryotes and eukaryotic cells as well. We expect SCIP to facilitate the finding of relationships between cellular processes, from small-scale (e.g. gene expression) to large-scale (e.g. cell division), in single cells and cell lineages. Availability and implementation: http://www.ca3-uninova.org/project_scip. Supplementary information: Supplementary data are available at Bioinformatics online.
Leonardo Martins, Ramakanth Neeli-Venkata, Samuel M. D. Oliveira, Antti Häkkinen, Andre S. Ribeiro, José Manuel Fonseca
Bioinform.6
2016 An Image Generator Platform to Improve Cell Tracking Algorithms - Simulation of Objects of Various Morphologies, Kinetics and Clustering
abstract
Several major advances in Cell and Molecular Biology have been made possible by recent advances in live-cell microscopy imaging. To support these efforts, automated image analysis methods such as cell segmentation and tracking during a time-series analysis are needed. To this aim, one important step is the validation of such image processing methods. Ideally, the “ground truth” should be known, which is possible only by manually labelling images or in artificially produced images. To simulate artificial images, we have developed a platform for simulating biologically inspired objects, which generates bodies with various morphologies and kinetics and, that can aggregate to form clusters. Using this platform, we tested and compared four tracking algorithms: Simple Nearest-Neighbour (NN), NN with Morphology and two DBSCAN-based methods. We show that Simple NN works well for small object velocities, while the others perform better on higher velocities and when clustering occurs. Our new platform for generating new benchmark images to test image analysis algorithms is openly available at (http://griduni.uninova.pt/Clustergen/ClusterGen_vl.0.zip).
Pedro Canelas, Leonardo Martins, André Mora, Andre S. Ribeiro, José Manuel Fonseca
SIMULTECH5
2014 FIF: A fuzzy information fusion algorithm based on multi-criteria decision making
Rita Almeida Ribeiro, António J. Falcão, André Mora, José Manuel Fonseca
Knowl. Based Syst.4
2013 A network and repository for online laboratory, based on ontology
abstract
Our proposal is to build a network of virtual laboratories and also use it as a global repository of online laboratory's and experiences.
Hamadou Saliah-Hassane, Raúl Cordeiro Correia, José Manuel Fonseca
EDUCON3
2013 Real-time image recovery using temporal image fusion
abstract
In computer vision systems an unpredictable image corruption can have significant impact on its usability. Image recovery methods for partial image damage, in particular in moving scenarios, can be crucial for recovering corrupted images. In these situations, image fusion techniques can be successfully applied to congregate information taken at different instants and from different points-of-view to recover damaged parts. In this article we propose a technique for temporal and spatial image fusion, based on fuzzy classification, which allows partial image recovery upon unexpected defects without user intervention. The method uses image alignment techniques and duplicated information from previous images to create fuzzy confidence maps. These maps are then used to detect damaged pixels and recover them using information from previous frames.
André Mora, José Manuel Fonseca, Rita Almeida Ribeiro
FUZZ-IEEE2
2013 A PSO/Snake Hybrid Algorithm for Determining Differential Rotation of Coronal Bright Points
Ehsan Shahamatnia, Ivan Dorotovic, Rita Almeida Ribeiro, José Manuel Fonseca
IJCCI4
2013 CellAging: a tool to study segregation and partitioning in division in cell lineages of Escherichia coli
abstract
MOTIVATION: Cell division in Escherichia coli is morphologically symmetric. However, as unwanted protein aggregates are segregated to the cell poles and, after divisions, accumulate at older poles, generate asymmetries in sister cells' vitality. Novel single-molecule detection techniques allow observing aging-related processes in vivo, over multiple generations, informing on the underlying mechanisms. RESULTS: CellAging is a tool to automatically extract information on polar segregation and partitioning in division of aggregates in E.coli, and on cellular vitality. From time-lapse, parallel brightfield and fluorescence microscopy images, it performs cell segmentation, alignment of brightfield and fluorescence images, lineage construction and pole age determination, and it computes aging-related features. We exemplify its use by analyzing spatial distributions of fluorescent protein aggregates from images of cells across generations. AVAILABILITY: CellAging, instructions and an example are available at http://www.cs.tut.fi/%7esanchesr/cellaging/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Antti Häkkinen, Anantha Barathi Muthukrishnan, André Mora, José Manuel Fonseca, Andre S. Ribeiro
Bioinform.4
2012 Euronet lab a cloud based laboratory environment
abstract
A large number of virtual and remote labs connected to the internet is already available nowadays. However, they usually are isolated and independent systems, unable to cooperate and complement each other. This lack of interconnection and interoperability leads, consequently, to the duplication of efforts in order to develop what could be easily shared and reused. Therefore, the integration of different platforms can speed up the development of virtual labs and downsize the barriers of using complementary systems that would represent an unachievable development task. In this paper one presents a proposal for the implementation of an open system that will be able to integrate different virtual lab platforms and components by interconnecting them and establishing communication mechanisms that will support understanding and agreement between heterogeneous systems. When one tries to interconnect systems developed on geographically distant places, often using different languages and different cultures, obstacles may arise. In this paper we present a proposal for a new system that allows users to do exactly this; to interconnect several virtual and remote labs through the internet, and to perform tests using components of several of these systems even if they are physically separated from each other.
Raúl Cordeiro Correia, José Manuel Fonseca, Andrew Donellan
EDUCON2
2010 Assessment of benefit vs. risk of drug therapy: The potential for outcome analysis with flexible models
abstract
Pharmaceutical companies face twin pressures of improving the throughput of new products and responding to increased requirements by regulatory bodies for risk evaluation and mitigation both pre- and post-marketing. This paper gives a brief overview of flexible outcome models to improve the accuracy of these studies. The focus is on the discovery of niche populations in secondary analysis and monitoring of adverse events in observational studies of new products. Analytical results illustrate the power of the methods and they can be mapped onto Boolean filters to represent populations with particular benefit/risk ratios.
Paulo J. G. Lisboa, Ana S. Fernandes, José Manuel Fonseca, Chris Bajdik, Elia Biganzoli
IJCNN3
2008 Missing Data Imputation in Longitudinal Cohort Studies: Application of PLANN-ARD in Breast Cancer Survival
abstract
Missing values are common in medical datasets and may be amenable to data imputation when modelling a given data set or validating on an external cohort. This paper discusses model averaging over samples of the imputed distribution and extends this approach to generic non-linear modelling with the Partial Logistic Artificial Neural Network (PLANN) regularised within the evidence-based framework with Automatic Relevance Determination (ARD). The study then applies the imputation to external validation over new patient cohorts, considering also the case of predictions made for individual patients. A prognostic index is defined for the non-linear model and validation results show that 4 statistically significant risk groups identified at the 95% level of confidence from the modelling data, from Christie Hospital (n=931), retain good separation during external validation with data from the British Columbia Cancer Agency (n=4,083).
Ana S. Fernandes, Ian H. Jarman, Terence A. Etchells, José Manuel Fonseca, Elia Biganzoli, Chris Bajdik, Paulo J. G. Lisboa
ICMLA4
2008 Stratification of Severity of Illness Indices: A Case Study for Breast Cancer Prognosis
Terence A. Etchells, Ana S. Fernandes, Ian H. Jarman, José Manuel Fonseca, Paulo J. G. Lisboa
KES (2)4
1992 Ship Noise Evaluation Based On Segmented Decision Trees
abstract
Signature recognition can be useful in a wide range of applications. A decision tree method for ship noise classification is presented. Thie ship noise, once transposed to the frequency's domain through the application of a bIi'r, is classified by a decision tree previously calculated during a training phase in which a significant set of situations must be shown to the algorithm. The tree calculation process is explained and results from real e xperiments a re presented. P arallel implementations for improvement of performance are suggested. A well suited architecture transputer based, is also presented for the problem solution.
José Manuel Fonseca, Fernando Moura-Pires
IROS1