A Mechanism for Dynamic Coordination of Multiple Robots

In this paper, we present a mechanism for coordinating multiple robots in the execution of cooperative tasks. The basic idea in the paper is to assign to each robot in the team, a role that determines its actions during the cooperation. The robots dynamically assume and exchange roles in a synchronized manner in order to perform the task successfully, adapting to unexpected events in the environment. We model this mechanism using a hybrid systems framework and apply it in different cooperative tasks: cooperative manipulation and cooperative search and transportation. Simulations and real experiments demonstrating the effectiveness of the proposed mechanism are presented

GEOBIT: A Geodesic-Based Binary Descriptor Invariant to Non-Rigid Deformations for RGB-D Images

International audienceAt the core of most three-dimensional alignment and tracking tasks resides the critical problem of point correspondence. In this context, the design of descriptors that efficiently and uniquely identifies keypoints, to be matched, is of central importance. Numerous descriptors have been developed for dealing with affine/perspective warps, but few can also handle non-rigid deformations. In this paper, we introduce a novel binary RGB-D descriptor invariant to iso-metric deformations. Our method uses geodesic isocurves on smooth textured manifolds. It combines appearance and geometric information from RGB-D images to tackle non-rigid transformations. We used our descriptor to track multiple textured depth maps and demonstrate that it produces reliable feature descriptors even in the presence of strong non-rigid deformations and depth noise. The experiments show that our descriptor outperforms different state-of-the-art descriptors in both precision-recall and recognition rate metrics. We also provide to the community a new dataset composed of annotated RGB-D images of different objects (shirts, cloths, paintings, bags), subjected to strong non-rigid deformations, to evaluate point correspondence algorithms

Project Freebird: An orbital transfer vehicle

Freebird is a space-based orbital transfer vehicle designed to repair and deorbit orbital assets. Freebird is based at International Space Station Alpha (ISSA) at an inclination of 51.6 deg and is capable of three types of missions: crewed and teleoperated LEO missions, and extended robotic missions. In a crewed local configuration, the vehicle can visit inclinations between 30.8 deg and 72.4 deg at altitudes close to 390 km. Adding extra fuel tanks extends this range of inclination up to 84.9 deg and down to 18.3 deg. Furthermore, removing the crew module, using the vehicle in a teleoperated manner, and operating with extra fuel tanks allows missions to polar and geosynchronous orbits. To allow for mission flexibility, the vehicle was designed in a semimodular configuration. The major system components include a crew module, a 'smart box' (which contains command, communications, guidance, and navigation equipment), a propulsion pack, extra fuel tanks, and a vehicle storage facility (VSF) for storage purposes. To minimize risk as well as development time and cost, the vehicle was designed using only proven technology or technology which is expected to be flight-qualified in time for the intended launch date of 2002. And, because Freebird carries crew and operates near the space station, it must meet or exceed the NASA reliability standard of 0.994, as well as other standard requirements for such vehicles. The Freebird program was conceived and designed as a way to provide important and currently unavailable satellite repair and replacement services of a value equal to or exceeding operational costs

Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects

Objectives: This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. Material and Methods: Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized presurgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). Results: As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm2 in the test group and 2 mm2 in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). Conclusions: The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions

Distribution and abundance of Pleuronectiformes larvae off Southeastern Brazil

The objective of this study was the description of the composition, abundance and density in horizontal and vertical distribution of Pleuronectiformes larvae on the southeastern Brazilian continental shelf. The samples were collected with bongo nets and a Multi Plankton Sampler (MPS), both in summer and winter 2002. A total of 352 flatfishes larvae were collected in summer and 343 in winter, representing three families and a total of 13 taxa: Paralichthyidae (Citharichthys cornutus, C. spilopterus, Citharichthys sp., Cyclopsetta chittendeni, Syacium spp., Etropus spp. and Paralichthys spp.), Bothidae (Bothus ocellatus and Monolene antillarum) and Cynoglossidae (Symphurus trewavasae, S. jenynsi, S. plagusia and S. ginsburgi). The most abundant taxa were Etropus spp., Syacium spp. and Bothus ocellatus. Etropus spp. occurred mainly as far out as the 200 m isobath and Syacium spp. from 100 m. B. ocellatus was present mainly in the oceanic zone between Ubatuba and Rio de Janeiro as from the 200 m isobath. The greatest average densities of these species occurred in the strata from 0 to 20 m depth in summer and between 20 and 40 m in winter

Impact of a pharmaceutical care programme on health-related quality of life among women with epilepsy: a randomised controlled trial (IPHIWWE study)

This paper was presented in part at the II Congreso Colombiano de Atención Farmacéutica, Medellín, Colombia, September 27, 2013.Background: Epilepsy is a complex chronic disorder which affects health-related quality of life (HRQOL), especially in women. Pharmaceutical care (PC) allows direct intervention between the pharmacist, the patient and the other healthcare team members to optimise treatments in order to reduce negative outcomes related to medication and contribute to improving HRQOL. The aim of the study was to establish the impact of the application of a pharmaceutical care programme on the HRQOL of women with epilepsy.Methods: This study is a pragmatic randomised controlled trial involving women with epilepsy (WWE) over 18 years of age. The intervention group (IG) received a pharmaceutical care programme consisting of medication review follow-up according to Dáder’s method, health education and therapeutic drug monitoring of anticonvulsants. The impact was assessed by changes in seizure frequency, in the self-administered questionnaires (the QOLIE-31, Liverpool AEP, CES-D, Haynes-Sackett test and Moriski-Green test) and between the first interview and the one at the end of six months of follow-up. A Student’s t-test was performed to compare the final QOLIE-31 score between groups and a paired Student’s t-test was used to determine the change in each group between the start and the end of follow-up.Results: One hundred eighty-two WWE entered the study and 144 (79.1%) completed it. The t-test for comparing the final QOLIE-31 scores between groups yielded a t = −2.166 and confidence interval (CI) (95%): −10.125; −0.4625, p-value =0.0319. The change (Δ) in the QOLIE-31 score for the IG was 12.45 points (p-value <0.001) and for the control group it was 2.61 (p-value =0.072). With 10.7 as the minimally important change we found a relative risk of 2.17 (CI: 1.37; 3.43) and a number needed to treat (NNT) of 3.5.Conclusions: The study demonstrated that the application of a pharmaceutical care programme significantly improves HRQOL in WWE. The NNT we found allows a recommendation to implement the PC programme for the additional benefit that would be obtained in patients’ HRQOL.This study was funded by a competitive investigator grant award from the Universidad Nacional de Colombia (Colombia) - Research Division of Bogotá (ref: 202010011419 Quipu Code)