Computationally efficient solutions for tracking people with a mobile robot: an experimental evaluation of Bayesian filters

Modern service robots will soon become an essential part of modern society. As they have to move and act in human environments, it is essential for them to be provided with a fast and reliable tracking system that localizes people in the neighbourhood. It is therefore important to select the most appropriate filter to estimate the position of these persons. This paper presents three efficient implementations of multisensor-human tracking based on different Bayesian estimators: Extended Kalman Filter (EKF), Unscented Kalman Filter (UKF) and Sampling Importance Resampling (SIR) particle filter. The system implemented on a mobile robot is explained, introducing the methods used to detect and estimate the position of multiple people. Then, the solutions based on the three filters are discussed in detail. Several real experiments are conducted to evaluate their performance, which is compared in terms of accuracy, robustness and execution time of the estimation. The results show that a solution based on the UKF can perform as good as particle filters and can be often a better choice when computational efficiency is a key issue

Social Activity Recognition on Continuous RGB-D Video Sequences

Modern service robots are provided with one or more sensors, often including RGB-D cameras, to perceive objects and humans in the environment. This paper proposes a new system for the recognition of human social activities from a continuous stream of RGB-D data. Many of the works until now have succeeded in recognising activities from clipped videos in datasets, but for robotic applications it is important to be able to move to more realistic scenarios in which such activities are not manually selected. For this reason, it is useful to detect the time intervals when humans are performing social activities, the recognition of which can contribute to trigger human-robot interactions or to detect situations of potential danger. The main contributions of this research work include a novel system for the recognition of social activities from continuous RGB-D data, combining temporal segmentation and classification, as well as a model for learning the proximity-based priors of the social activities. A new public dataset with RGB-D videos of social and individual activities is also provided and used for evaluating the proposed solutions. The results show the good performance of the system in recognising social activities from continuous RGB-D data

Social activity recognition based on probabilistic merging of skeleton features with proximity priors from RGB-D data

Social activity based on body motion is a key feature for non-verbal and physical behavior defined as function for communicative signal and social interaction between individuals. Social activity recognition is important to study human-human communication and also human-robot interaction. Based on that, this research has threefold goals: (1) recognition of social behavior (e.g. human-human interaction) using a probabilistic approach that merges spatio-temporal features from individual bodies and social features from the relationship between two individuals; (2) learn priors based on physical proximity between individuals during an interaction using proxemics theory to feed a probabilistic ensemble of activity classifiers; and (3) provide a public dataset with RGB-D data of social daily activities including risk situations useful to test approaches for assisted living, since this type of dataset is still missing. Results show that using the proposed approach designed to merge features with different semantics and proximity priors improves the classification performance in terms of precision, recall and accuracy when compared with other approaches that employ alternative strategies

Automatic Detection of Human Interactions from RGB-D Data for Social Activity Classification

We present a system for temporal detection of social interactions. Many of the works until now have succeeded in recognising activities from clipped videos in datasets, but for robotic applications, it is important to be able to move to more realistic data. For this reason, the proposed approach temporally detects intervals where individual or social activity is occurring. Recognition of human activities is a key feature for analysing the human behaviour. In particular, recognition of social activities is useful to trigger human-robot interactions or to detect situations of potential danger. Based on that, this research has three goals: (1) define a new set of descriptors, which are able to characterise human interactions; (2) develop a computational model to segment temporal intervals with social interaction or individual behaviour; (3) provide a public dataset with RGB-D data with continuous stream of individual activities and social interactions. Results show that the proposed approach attained relevant performance with temporal segmentation of social activities

Environmental sensitivity mapping to oil spill and response actions for shoreline and portuary zone of Imbituba, SC, Brazil

Environmental Sensitivity Index maps (ESI) have been produced for the shoreline of Imbituba, located in the southern coast of Santa Catarina State, Brazil, in the scales of 1:50,000 and 1:10,000. Adequate cleanup procedures were selected and indicated for each coastal segment identified, in accordance to expected oil behavior in each one. The study area comprises an important environmental protection area for right whales (Eubalaena glacialis) reproduction. The ESI maps include information for three main components: sensitive biological resources, human-uses resources and shoreline habitats. Data of biological resources and some human-use information were obtained from an integrated project named Environmental Sensitivity Index Maps of Santos Sedimentary Marine Basin. Shoreline habitats data were obtained in field survey. Methodology applied was that proposed by the Brazilian Environment Ministry (MMA), adapted from the National Oceanic and Atmosphere Administration (NOAA), with the aid of remote sensing and geographical information system (SIG). Twenty segments were identified in the study area, comprising 15 km of shoreline. Only 6 different ESI were identified, with the most representative in extension being the ESI 3 (dissipative exposed beaches)

Wastewater Treatment Using Alkali-Activated-Based Sorbents Produced from Blast Furnace Slag

Currently, slags from secondary steel production, foundries, and blast furnaces represent a major environmental problem since they end up mainly in landfills, and their valorization would bring undeniable advantages both to environment and economy. Moreover, the removal of heavy metal ions from mines wastewater is one of the challenges of the last decades, and adsorption has been proposed as one of the most promising techniques for this purpose. In this context, the use of alkali-activated slags as sorbent can be a good opportunity to develop low cost, environmentally friendly, and sustainable materials. Accordingly, wastewater decontamination by adsorption over a porous monolithic bed made of alkali-activated hydraulic binders is proposed. Alkali-activated materials were prepared using slags from the metallurgical industry and reacted with an alkaline component (high alumina calcium aluminate cement, CAC 80) at ambient conditions. The obtained monolithic foams were tested to evaluate the uptake efficiency towards metal capture. Solutions containing Cu(II), Fe(III), Ni(II), Mn(II), and simulating the metal concentrations of a real mine effluent were tested, both in single- and multi-ion solutions. Promising capture efficiency, values of 80–100% and of 98–100% in the case of the single ion and of the multi-ion solutions were obtained, respectively

Malformazione arterovenosa della mandibola. Caso clinico e revisione della letteratura

Le malformazioni arterovenose (MAV) del distretto cervico-facciale sono patologie rare e potenzialmente letali a causa delle imponenti emorragie che possono determinare. Il trattamento dipende dall'età del paziente, dalla sede, dall'estensione e dalla tipologia della malformazione. La terapia endovascolare è efficace nella maggior parte dei casi che presentano un'estensione limitata. In casi selezionati, e sempre in associazione con l'embolizzazione, si può ricorrere alla chirurgia. Nel presente articolo riportiamo il caso di una giovane donna affetta da un'estesa MAV dell'emimandibola e della regione sottomandibolare sinistra. Viene inoltre effettuata una revisione della letteratura prodotta su questo argomento con particolare attenzione alla strategia di trattamento

Biomonitoramento ativo de metais traço e efeito biológico em mexilhões transplantados para área de influência de efluente de indústria de beneficiamento de aço - Fase I

Preliminary results from an environmental monitoring program of an industrial submarine outflow are presented. Introduced mussels technique with Perna perna was applied. Two evaluations were carried out; one thirty days after the transplant and, another one, sixty days after the first one. Trace metal bioaccumulation and the associated cellular damage were determined. In the first evaluation, in the beginning of the industrial activity, concentrations significantly higher of some metals in mussels of the area of the emissary in comparison with the control site had been registered. In the second evaluation higher concentrations were recorded only for Cd, Zn and Ni at submarine outflow zone. Despite this, the recorded concentrations remained in the range considered normal for the studied species and below of the maximum level accepted by law for human consumption. The Neutral Red Assay, the biomarker applied, evidenced no cellular damage.Preliminary results from an environmental monitoring program of an industrial submarine outflow are presented. Introduced mussels technique with Perna perna was applied. Two evaluations were carried out; one thirty days after the transplant and, another one, sixty days after the first one. Trace metal bioaccumulation and the associated cellular damage were determined. In the first evaluation, in the beginning of the industrial activity, concentrations significantly higher of some metals in mussels of the area of the emissary in comparison with the control site had been registered. In the second evaluation higher concentrations were recorded only for Cd, Zn and Ni at submarine outflow zone. Despite this, the recorded concentrations remained in the range considered normal for the studied species and below of the maximum level accepted by law for human consumption. The Neutral Red Assay, the biomarker applied, evidenced no cellular damage

RESULTADOS PRELIMINARES DA DISTRIBUIÇÃO DE FÓSFORO E SUAS FORMAS NOS SEDIMENTOS DA PLATAFORMA CONTINENTAL DO ESTADO DE SANTA CATARINA

Distribuition of phosphorus in marine sediments have been recognized as a useful tool for the knowledgement of its geochemical cicle, that have been undergoing chances by human actions. Marine sediments represents the major reservoir of this constituint, where processes take place and control its disponibility to water column. Differents forms of phosphorus were determined by sequencial extrations in 27 samples of bottom sediment collected in the inner shelf off Santa Catarina. The aim of this study was to investigate the distribuition of phosphorus in the sequencial extrated frations and the relationship with sediment facies. The highest total phosphorus concentrations have been related to fine grained sediments. Although, there were some differences between samples with similar sedimentar patterns. Iron plus aluminium phosphate has been showed high concentrations in the neigborhood of river mounths, declining off shore. Calcium phosphate was the predominant form in most samples.O estudo de fósforo em sedimentos marinhos tem sido utilizado como importante ferramenta para compreensão do ciclo geoquímico deste nutriente, o qual vem sendo alterado pela ação antropogênica. Os sedimentos marinhos representam o depósito final deste constituinte e, dependendo dos processos de interação química que ali ocorrem, podem ser responsáveis por sua maior ou menor disponibilidade para a coluna d’água. Neste estudo foram determinadas as diferentes formas de fósforo, através do método de extração sequencial (modificado de SILVEIRA, 1993), em 27 amostras de sedimentos superficiais coletados na plataforma interna do litoral centro-norte catarinense. O objetivo era verificar a distribuição de fósforo e suas formas de acordo com as fácies sedimentares encontradas na área de estudo. As concentrações de fósforo total variaram entre 1,27 a 18,77 µmol/g, com as mais elevadas estando associadas aos sedimentos finos, embora tenham ocorrido diferenças entre fácies com características granolumétricas similares. O fosfato de ferro + alumínio apresentou concentrações mais altas próximo as desembocaduras dos rios diminuindo com o aumento da distância da linha de costa, indicando o aporte continental. A forma predominante na maioria das amostras foi o fosfato de cálcio que apresentou uma relação direta com a profundidade

Nanoscale Assembly of Functional Peptides with Divergent Programming Elements

Self-assembling peptides are being applied both in the biomedical area and as building blocks in nanotechnology. Their applications are closely linked to their modes of self-assembly, which determine the functional nanostructures that they form. This work brings together two structural elements that direct nanoscale self-association in divergent directions: proline as a β-breaker and the β-structure-associated diphenylalanine motif, into a single tripeptide sequence. Amino acid chirality was found to resolve the tension inherent to these conflicting self-assembly instructions. Stereoconfiguration determined the ability of each of the eight possible Pro-Phe-Phe stereoisomers to self-associate into diverse nanostructures, including nanoparticles, nanotapes, or fibrils, which yielded hydrogels with gel-to-sol transition at a physiologically relevant temperature. Three single-crystal structures and all-atom molecular dynamics simulations elucidated the ability of each peptide to establish key interactions to form long-range assemblies (i,e., stacks leading to gelling fibrils), medium-range assemblies (i.e., stacks yielding nanotapes), or short-range assemblies (i.e., dimers or trimers that further associated into nanoparticles). Importantly, diphenylalanine is known to serve as a binding site for pathological amyloids, potentially allowing these heterochiral systems to influence the fibrillization of other biologically relevant peptides. To probe this hypothesis, all eight Pro-Phe-Phe stereoisomers were tested in vitro on the Alzheimer's disease-associated Aβ(1-42) peptide. Indeed, one nonfibril-forming stereoisomer effectively inhibited Aβ fibrillization through multivalent binding between diphenylalanine motifs. This work thus defined heterochirality as a useful feature to strategically develop future therapeutics to interfere with pathological processes, with the additional value of resistance to protease-mediated degradation and biocompatibility