634 research outputs found

    Fuzzy Gain-Scheduling PID for UAV Position and Altitude Controllers

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    Unmanned aerial vehicle (UAV) applications have evolved to a wide range of fields in the last decade. One of the main challenges in autonomous tasks is the UAV stability during maneuvers. Thus, attitude and position control play a crucial role in stabilizing the vehicle in the desired orientation and path. Many control techniques have been developed for this. However, proportional integral derivative (PID) controllers are often used due their structure and efficiency. Despite PID’s good performance, different requirements may be present at different mission stages. The main contribution of this research work is the development of a novel strategy based on a fuzzy-gain scheduling mechanism to adjust the PID controller to stabilize both position and altitude. This control strategy must be effective, simple, and robust to uncertainties and external disturbances. The Robot Operating System (ROS) integrates the proposed system and the flight control unit. The obtained results showed that the proposed approach was successfully applied to the trajectory tracking and revealed a good performance compared to conventional PID and in the presence of noises. In the tests, the position controller was only affected when the altitude error was higher, with an error of 2% lower.publishedVersio

    Heterogeneous Multi-Robot Collaboration for Coverage Path Planning in Partially Known Dynamic Environments

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    This research presents a cooperation strategy for a heterogeneous group of robots that comprises two Unmanned Aerial Vehicles (UAVs) and one Unmanned Ground Vehicles (UGVs) to perform tasks in dynamic scenarios. This paper defines specific roles for the UAVs and UGV within the framework to address challenges like partially known terrains and dynamic obstacles. The UAVs are focused on aerial inspections and mapping, while UGV conducts ground-level inspections. In addition, the UAVs can return and land at the UGV base, in case of a low battery level, to perform hot swapping so as not to interrupt the inspection process. This research mainly emphasizes developing a robust Coverage Path Planning (CPP) algorithm that dynamically adapts paths to avoid collisions and ensure efficient coverage. The Wavefront algorithm was selected for the two-dimensional offline CPP. All robots must follow a predefined path generated by the offline CPP. The study also integrates advanced technologies like Neural Networks (NN) and Deep Reinforcement Learning (DRL) for adaptive path planning for both robots to enable real-time responses to dynamic obstacles. Extensive simulations using a Robot Operating System (ROS) and Gazebo platforms were conducted to validate the approach considering specific real-world situations, that is, an electrical substation, in order to demonstrate its functionality in addressing challenges in dynamic environments and advancing the field of autonomous robots.The authors also would like to thank their home Institute, CEFET/RJ, the federal Brazilian research agencies CAPES (code 001) and CNPq, and the Rio de Janeiro research agency, FAPERJ, for supporting this work.info:eu-repo/semantics/publishedVersio

    Cross-Cultural Adaptation and Validation of SNOT-20 in Portuguese

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    Introduction. Chronic rhinosinusitis is a highly prevalent disease, so it is necessary to create valid instruments to assess the quality of life of these patients. The SNOT-20 questionnaire was developed for this purpose as a specific test to evaluate the quality of life related to chronic rhinosinusitis. It was validated in the English language, and it has been used in most studies on this subject. Currently, there is no validated instrument for assessing this disease in Portuguese. Objective. Cross-cultural adaptation and validation of SNOT-20 in Portuguese. Patients and Methods. The SNOT-20 questionnaire underwent a meticulous process of cross-cultural adaptation and was evaluated by assessing its sensitivity, reliability, and validity. Results. The process resulted in an intelligible version of the questionnaire, the SNOT-20p. Internal consistency (Cronbach's alpha = 0.91, P < .001), reliability testing-retesting (r = 0.994, P < .001), content validity, validity of discrimination of patients without chronic rhinosinusitis (U = 44, P < .0001) and assessment of sensitivity to change (SRM = 1.53 and 1.09) were evaluated. Conclusion. We conducted a successful process of cross-cultural adaptation and validation of the SNOT-20 questionnaire into Portuguese

    Evaluation of Jackknife and Bootstrap for Defining Confidence Intervals for Pairwise Agreement Measures

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    Several research fields frequently deal with the analysis of diverse classification results of the same entities. This should imply an objective detection of overlaps and divergences between the formed clusters. The congruence between classifications can be quantified by clustering agreement measures, including pairwise agreement measures. Several measures have been proposed and the importance of obtaining confidence intervals for the point estimate in the comparison of these measures has been highlighted. A broad range of methods can be used for the estimation of confidence intervals. However, evidence is lacking about what are the appropriate methods for the calculation of confidence intervals for most clustering agreement measures. Here we evaluate the resampling techniques of bootstrap and jackknife for the calculation of the confidence intervals for clustering agreement measures. Contrary to what has been shown for some statistics, simulations showed that the jackknife performs better than the bootstrap at accurately estimating confidence intervals for pairwise agreement measures, especially when the agreement between partitions is low. The coverage of the jackknife confidence interval is robust to changes in cluster number and cluster size distribution

    E-Debitum: managing software energy debt

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    35th IEEE/ACM International Conference on Automated Software Engineering Workshops (ASEW ’20) - International Workshop on Sustainable Software Engineering (SUSTAIN-SE)This paper extends previous work on the concept of a new software energy metric: Energy Debt. This metric is a reflection on the implied cost, in terms of energy consumption over time, of choosing an energy flawed software implementation over a more robust and efficient, yet time consuming, approach. This paper presents the implementation a SonarQube tool called E-Debitum which calculates the energy debt of Android applications throughout their versions. This plugin uses a robust, well defined, and extendable smell catalogue based on current green software literature, with each smell defining the potential energy savings. To conclude, an experimental validation of E-Debitum was executed on 3 popular Android applications with various releases, showing how their energy debt fluctuated throughout releases.This work is financed by National Funds through the Portuguese funding agency, FCT -Fundação para a Ciência e a Tecnologia within project UIDB/50014/2020

    Quality of life, compliance, safety and effectiveness in fit older metastatic colorectal patients with cancer treated in first-line with chemotherapy plus cetuximab: A restrospective analysis from the ObservEr study

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    Abstract Objectives The influence of age ( KRAS wild type (WT) metastatic colorectal cancer (mCRC). Methods 225 patients of the Observed study (PS 0-1) were retrieved based on age ( Results The two patient groups (141  p  = 0.002), which is likely due to higher proportions of metastatic resection (27.0% vs 8.3%; p  = 0.001) and utilization of second-line therapy in younger group (58.9% vs 42.9%; p  = 0.028). Conclusion The current data suggest that fit older patients with mCRC can be safely treated with a cetuximab-based therapy, as QoL and safety profile do not seem to be affected by age. In addition, age did not impact the choice of chemotherapy to be associated to cetuximab and treatment compliance

    HPA e Nitro-HPA em Ambiente Semifechado Impactado por Emissão da Combustão de Diesel/Biodiesel (B5)

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    In order to verify the presence of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAH (NPAH) associated with the fine fraction of particulate matter (PM1.0 and PM2.5) from the combustion of diesel/biodiesel mixture (B5), daily samples were carried out in the urban bus station of Londrina. A high performance liquid chromatography with mass spectrometry (LC-APCI-MS) was used for the determination of nitro-PAH and the PAHs were determined by high performance liquid chromatography equipped with fluorescence detector (LC-FLD). 9 PAHs and 1-nitropyrene were determined. The concentrations of the PAHs with 4 to 6 rings (fluoranthene, pyrene, crysene, benzo(b)fluoranthene, benzo(k)fluoranthene and dibenzo(a,h)antharacene) were higher in comparison to the lighter PAHs (acenaphthene, fluorene and anthracene). The ∑PAH associated to the PM1.0 corresponded to 66% of the PM2.5 with concentrations that exceed the levels recommended by WHO. The diagnostic ratios (DR) of PAHs and NPAH were calculated and the results suggest diesel/biodiesel (B5) emissions. The use of biofuel in Brazil is encouraged and the monitoring of changes in emissions arising from combustion processes is important and necessary to follow the change of air quality and the impact on the environment.  DOI: http://dx.doi.org/10.17807/orbital.v7i3.73

    Randomized trial on adjuvant treatment with FOLFIRI followed by docetaxel and cisplatin versus 5-fluorouracil and folinic acid for radically resected gastric cancer

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    Some trial have demonstrated a benefit of adjuvant fluoropirimidine with or without platinum compounds compared with surgery alone. ITACA-S study was designed to evaluate whether a sequential treatment of FOLFIRI [irinotecan plus 5-fluorouracil/folinic acid (5-FU/LV)] followed by docetaxel plus cisplatin improves disease-free survival in comparison with 5-FU/LV in patients with radically resected gastric cancer. Patients with resectable adenocarcinoma of the stomach or gastroesophageal junction were randomly assigned to either FOLFIRI (irinotecan 180 mg/m(2) day 1, LV 100 mg/m(2) as 2 h infusion and 5-FU 400 mg/m(2) as bolus, days 1 and 2 followed by 600 mg/m(2)/day as 22 h continuous infusion, q14 for four cycles) followed by docetaxel 75 mg/m(2) day 1, cisplatin 75 mg/m(2) day 1, q21 for three cycles (sequential arm) or De Gramont regimen (5-FU/LV arm). From February 2005 to August 2009, 1106 patients were enrolled, and 1100 included in the analysis: 562 in the sequential arm and 538 in the 5-FU/LV arm. With a median follow-up of 57.4 months, 581 patients recurred or died (297 sequential arm and 284 5-FU/LV arm), and 483 died (243 and 240, respectively). No statistically significant difference was detected for both disease-free [hazard ratio (HR) 1.00; 95% confidence interval (CI): 0.85-1.17; P = 0.974] and overall survival (OS) (HR 0.98; 95% CI: 0.82-1.18; P = 0.865). Five-year disease-free and OS rates were 44.6% and 44.6%, 51.0% and 50.6% in the sequential and 5-FU/LV arm, respectively. A more intensive regimen failed to show any benefit in disease-free and OS versus monotherapy
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