Impact of Ground Truth Annotation Quality on Performance of Semantic Image Segmentation of Traffic Conditions

Preparation of high-quality datasets for the urban scene understanding is a labor-intensive task, especially, for datasets designed for the autonomous driving applications. The application of the coarse ground truth (GT) annotations of these datasets without detriment to the accuracy of semantic image segmentation (by the mean intersection over union - mIoU) could simplify and speedup the dataset preparation and model fine tuning before its practical application. Here the results of the comparative analysis for semantic segmentation accuracy obtained by PSPNet deep learning architecture are presented for fine and coarse annotated images from Cityscapes dataset. Two scenarios were investigated: scenario 1 - the fine GT images for training and prediction, and scenario 2 - the fine GT images for training and the coarse GT images for prediction. The obtained results demonstrated that for the most important classes the mean accuracy values of semantic image segmentation for coarse GT annotations are higher than for the fine GT ones, and the standard deviation values are vice versa. It means that for some applications some unimportant classes can be excluded and the model can be tuned further for some classes and specific regions on the coarse GT dataset without loss of the accuracy even. Moreover, this opens the perspectives to use deep neural networks for the preparation of such coarse GT datasets.Comment: 10 pages, 6 figures, 2 tables, The Second International Conference on Computer Science, Engineering and Education Applications (ICCSEEA2019) 26-27 January 2019, Kiev, Ukrain

Synthesis and characterization of a composite organic semiconductor (curcumin-paracetamol/TiO2)

The aim of this work is to study some physical and chemical properties of an organic semiconductor (OSc)/x%titanium dioxide (TiO2) heterosystem (with 0 ≤ x ≤ 20%) (OScs/x%TiO2). The OSc is obtained from pure curcumin and paracetamol as starting molecules. The synthesis methodology of the mixtures of OScs/x%TiO2 heterosystem involves a microwave-assisted multicomponent reaction using curcumin, paracetamol, and TiO2 as a heterogeneous solution. All mixtures were analyzed by Fourier-transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis/differential thermal analysis, X-ray diffraction, ultraviolet–visible spectroscopy, and scanning electron microscopy. The results obtained show a new nanocomposite with interesting pharmaceutical, optical, electronic, and structural properties, which can be used in the fields of energy production, water purification, and air purification, as a biomaterial and for electronic applications

Theoretical Kinetics Investigation of Krypton Dielectric Barrier Discharge for UV Lamp

International audienceThis work presents an electric and kinetic study of homogeneous dielectric barrier discharge (DBD) in pure krypton (Kr). The electrical characterization and kinetic analyses of the DBD in Kr are performed. The plasma formation in DBD, excited by sinusoidal voltage at high pressure, was studied. The discharge development, with homogeneous model approach and using extended kinetic scheme, is simulated. The study is based on a spatial homogeneity model including the plasma chemistry, the electrical circuit and the Boltzmann equations’. The temporal variations of discharge voltage, dielectrics voltage, discharge current, electric field and species concentrations are calculated. The plasma kinetics is discussed with the aim to finding the optimal efficiency. The photon generation, under typical operating conditions, was investigated and discussed. The effect of some parameters on the excilamp like pressure, applied voltage, and frequency are investigated in order to identify the optimal parameters for maximum luminous efficiency in the UV range

Combustion of vegetable oils under optimized conditions of atomization and granulometry in a modified fuel oil burner

The use of vegetable oils in burners represents an attractive alternative to the use of heating fuel oil (HFO) in heat production for domestic heating, small industrial units, drying of various products etc. In this work, a characterization of the combustion of cottonseed oil in a modified burner (type Riello 40N10) was performed to assess its ability to achieve proper combustion of vegetable oils in optimized conditions of atomization and granulometry. The quality of the combustion has been evaluated by the analysis of combustion products (CO, O-2, CO2, NO, NO2, SO2) and organic compounds including PAHs. Results show that the modifications made on the burner type 40N10 can achieve suitable spray conditions and give particle size within the recommended values for burners. In the case of Riello 40N10 burner, a fuel pressure of 28 bars is adequate and the minimum temperature required for oil preheating is 125 degrees C. When these conditions are achieved, cottonseed oil combustion leads to the emission of non-condensable gases and the organic compounds species as well as their concentration close to those of HFO. (C) 2013 Elsevier Ltd. All rights reserved