1,228 research outputs found
Robot bin picking: 3D pose retrieval based on Point Cloud Library
This work covers the problem of object recognition and 6 DOF pose estimation in a point cloud data structure, using PCL (Point Cloud Library). The result of the computation will be used for bin picking purposes, but it can also be applied to any context that require to find and align a specific pattern. The goal is to align an object model to all the visible instances of it in an input cloud. The algorithm that will be presented is based on local geometry FPFH descriptors that are computed on a set of uniform keypoints of the point clouds. Correspondences (best match) between such features will be filtered with RANSAC procedure: from this data comes a rough alignment, that will be refined by ICP algorithm. Robust dedicated validation functions will guide the entire process with a greedy approach. Parallelism has also been implemented using OpenMP API. Time and effectiveness will be deeply discussed, since the target industrial application imposes strict constraints of performance and robustness. The result of the proposed solution is really appreciable, since the algorithm is able to recognize almost all the present objects, with a minimal percentage of false negatives and an almost zero false positives rate. Experiments have been conducted on a large dataset, that was acquired with a triangulation system made up by one camera and two intersecting lasers as structured light sources. Such vision system has been mounted first on a fixed position over a conveyor belt, then on a moving robotic arm, in order to cover a larger areope
Thromboprophylaxis in day surgery
AbstractMany patients undergoing day surgery are at low-risk of venous thromboembolic events. However, given that pulmonary embolism is the most common preventable cause of hospital death, the risk-benefit profile of thromboprophylaxis should be accurately balanced. In this narrative review, we will briefly discuss some topics of thromboprohylaxis in ambulatory surgical procedures: venous thromboembolic risk stratification, venous thromboembolic risk during laparoscopic surgery, use of antithrombotic drugs in case of neuraxial anesthesia/analgesia, American College of Chest Physicians recommendations for thromboprophylaxis
Correction to: Reversal agents for oral anticoagulant-associated major or life-threatening bleeding
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Pharmacological thromboprophylaxis in acutely ill medical patients: some work remains to be done
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A long-term source apportionment of PM2.5 in New York State during 2005–2016
The development and implementation of effective policies for controlling PM2.5 mass concentrations and protecting human health depend upon the identification and apportionment of its sources. In this study, the PM2.5 sources affecting 6 urban and 2 rural sites across New York State during the period 2005–2016 were determined. The extracted profiles were compared to identify state-wide common profiles. The source contributions provide detailed, long-term quantification of the emission sources across the state during the investigated period (2005–2016). Seven factors were common to all sites: secondary sulfate, secondary nitrate, spark-ignition emissions, diesel emissions, road dust, biomass burning, and pyrolyzed organic (OP) rich. The largest contributors were secondary sulfate, secondary nitrate, spark-ignition (gasoline), diesel, and OP-rich. Secondary sulfate concentrations ranged from 2.3 μg m−3 at Whiteface to 3.2 μg m−3 at Buffalo and the Bronx. The highest secondary sulfate fractional contributions were found at the rural sites (∼46% of PM2.5 mass) also showed the highest OP-rich contributions (∼19%). Secondary nitrate showed the highest concentrations at the urban sites representing ∼17% of PM2.5 mass (1.6 ± 0.3 μg m−3 on average). Urban sites also showed the highest average spark-ignition concentrations (1.7 ± 0.2 μg m−3, ∼18%) and diesel emissions (1.0 ± 0.2 μg m−3, ∼10%). During this period, secondary sulfate concentrations declined likely related to the implementation of mitigation strategies for controlling SO2 emissions and the changing economics of electricity generation. Similarly, diesel and secondary nitrate showed decreases in concentrations likely associated with the introduction of emissions controls and improved quality fuels for heavy-duty diesel on-road trucks and buses. Spark-ignition concentrations showed an increase across the state during 2014–2016 associated with the increase of registered vehicles in New York State
PM2.5 and gaseous pollutants in New York State during 2005–2016: Spatial variability, temporal trends, and economic influences
Over the past decades, mitigation strategies have been adopted both by federal and state agencies in the United States (US) to improve air quality. Between 2007 and 2009, the US faced a financial/economic crisis that lowered activity and reduced emissions. At the same time, changes in the prices of coal and natural gas drove a shift in fuels used for electricity generation. Seasonal patterns, diel cycles, spatial gradients, and trends in PM2.5 and gaseous pollutants concentrations (NOx, SO2, CO and O3) monitored in New York State (NYS) from 2005 to 2016 were examined. Relationships between ambient concentrations, changes in NYS emissions retrieved from the US EPA trends inventory, and economic indicators were studied. PM2.5 and primary gaseous pollutants concentrations decreased across NYS. By 2016, PM2.5 and SO2 attained relatively homogeneous concentrations across the state. PM2.5 concentrations decreased significantly at all sites. Similarly, SO2 concentrations declined at all sites within this period, with the highest slopes observed at the urban sites. Reductions in NOx emissions likely contributed to summertime average ozone reductions. NOx and VOCs controls reduced O3 peak concentrations at rural and suburban sites as seen in significant relationships between the annual O3 4th-highest daily maximum 8-h concentrations and estimated NOx emissions at rural and suburban sites (r2 ∼ 0.7). Spring maxima were not reduced with most sites showing insignificant slopes or significant positive slopes (e.g., +2.6% y−1 and +2% y−1, at CCNY and PFI, respectively). Increases in autumn and winter ozone concentrations were found (e,g., 6.6 ± 0.4% y−1 on average in New York City). Significant relationships were observed between PM2.5, primary pollutants, and economic indicators. Overall, a decrease in electricity generation with coal, and the simultaneous increase in natural gas consumption for power generation, led to a decrease in PM2.5 and gaseous pollutants concentrations
La green economy e la distruzione creatrice di lavoro
La green economy come soluzione alle molteplici crisi attualie il suo impatto nel mondo del lavoro: i green jobsopenTesi non accessibile fino a 18 Settembre 2020 per motivi correlati alla proprietà intellettuale dell'autor
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