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With the latest advances in image sensor technology, cameras are able to generate video with tens of megapixels per frame. These high resolution videos streams offer great potential to be used in the surveillance domain. For groun...
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With the latest advances in image sensor technology, cameras are able to generate video with tens of megapixels per frame. These high resolution videos streams offer great potential to be used in the surveillance domain. For ground based systems, gigapixel streams are already used with great effect as illustrated by the ICME 2019 crowd counting challenge. However, for Unmanned Aerial Vehicles (UAVs), this vast stream of data exceeds the limit of transmission bandwidth to send this data back to the ground. On board data analysis and selection is thus required to use and benefit from high resolution cameras. This paper presents a result of the CAVIAR project, where a combination of hardware and algorithms was designed to answer the question: "how to exploit a high resolution high frame rate camera on board a UAV?'. With the associated size, weight and power limitations, we implement data reduction by deploying deep learning on hardware to find the relevant information and transmit it to an operator station. The proposed solution aims at employing the high resolution potential of the sensor only onto objects of interest. We encode and transmit the identified regions containing those objects of interest (ROI) at the original resolution and framerate, while also transmitting the downscaled background to provide context for an operator. We demonstrate using a 35 fps, 65 Megapixel camera that this set-up indeed saves considerable bandwidth while retaining all important video data at high quality at the same time.
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摘要 :
With the latest advances in image sensor technology, cameras are able to generate video with tens of megapixels per frame. These high resolution videos streams offer great potential to be used in the surveillance domain. For groun...
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With the latest advances in image sensor technology, cameras are able to generate video with tens of megapixels per frame. These high resolution videos streams offer great potential to be used in the surveillance domain. For ground based systems, gigapixel streams are already used with great effect as illustrated by the ICME 2019 crowd counting challenge. However, for Unmanned Aerial Vehicles (UAVs), this vast stream of data exceeds the limit of transmission bandwidth to send this data back to the ground. On board data analysis and selection is thus required to use and benefit from high resolution cameras. This paper presents a result of the CAVIAR project, where a combination of hardware and algorithms was designed to answer the question: "how to exploit a high resolution high frame rate camera on board a UAV?'. With the associated size, weight and power limitations, we implement data reduction by deploying deep learning on hardware to find the relevant information and transmit it to an operator station. The proposed solution aims at employing the high resolution potential of the sensor only onto objects of interest. We encode and transmit the identified regions containing those objects of interest (ROI) at the original resolution and framerate, while also transmitting the downscaled background to provide context for an operator. We demonstrate using a 35 fps, 65 Megapixel camera that this set-up indeed saves considerable bandwidth while retaining all important video data at high quality at the same time.
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This paper presents results of the work on the validation and optimization of a Computational Fluid Dynamics (CFD) method used as a development tool, and on the integration of the CFD simulation in the development process. For val...
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This paper presents results of the work on the validation and optimization of a Computational Fluid Dynamics (CFD) method used as a development tool, and on the integration of the CFD simulation in the development process. For validation purposes, simulations of air flows around the well known Ahmed body and the SAE Notchback Reference model, as well as a detailed 1:4 car model, have been carried out. Finally, the method is used to predict the aerodynamic forces on a real vehicle. The applied CFD method yielded good results for the academic examples, but when applying the method to industrial flows, deviations from measurement results are observed. The reasons may be, on the one hand, a weakness of CFD in predicting flow separation accurately, but, on the other hand, also the strong dependency of measurement results on the wind tunnel used. As a consequence, MAGNA STEYR does not use CFD for the validation of wind tunnel tests in the aerodynamic development process, but rather for active development and optimization. The paper shows that the effect of a modified vehicle shape with regard to drag and lift can be predicted with CFD, without the need to perform wind tunnel tests.
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The LYOT (LYman Orbiting Telescope) solar mission is proposed to be implemented on a micro-satellite of CNES (France) under phase A study. It includes two main instruments, which image the solar disk and the low corona up to 2.5 R...
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The LYOT (LYman Orbiting Telescope) solar mission is proposed to be implemented on a micro-satellite of CNES (France) under phase A study. It includes two main instruments, which image the solar disk and the low corona up to 2.5 R_o in the H I Lyman-α line at 121.6 nm. The spatial resolution is about 1" for the disk and 2.5" for corona. It also carries an EIT-type telescope in the He II (30.4 nm) line. The coronagraph needs a super polished mirror at the entrance pupil to minimize the light scattering. Gratings and optical filters are used to select the Lyman-α wavelength. VUV cameras with 2048 x 2048 pixels record solar images up to every 10 seconds. The satellite operates at a high telemetry rate (more than 100 kb/s, after onboard data compression). The envisaged orbits are either geostationary or heliosynchronous. Possible launch dates could be end of 2006-beginning of 2007.
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摘要 :
The LYOT (LYman Orbiting Telescope) solar mission is proposed to be implemented on a micro-satellite of CNES (France) under phase A study. It includes two main instruments, which image the solar disk and the low corona up to 2.5 R...
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The LYOT (LYman Orbiting Telescope) solar mission is proposed to be implemented on a micro-satellite of CNES (France) under phase A study. It includes two main instruments, which image the solar disk and the low corona up to 2.5 R_o in the H I Lyman-α line at 121.6 nm. The spatial resolution is about 1" for the disk and 2.5" for corona. It also carries an EIT-type telescope in the He II (30.4 nm) line. The coronagraph needs a super polished mirror at the entrance pupil to minimize the light scattering. Gratings and optical filters are used to select the Lyman-α wavelength. VUV cameras with 2048 x 2048 pixels record solar images up to every 10 seconds. The satellite operates at a high telemetry rate (more than 100 kb/s, after onboard data compression). The envisaged orbits are either geostationary or heliosynchronous. Possible launch dates could be end of 2006-beginning of 2007.
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Thin films of the polyaniline emeraldine salts of paratoluenesulphonic acid and phenylphosphonic acid have been employed to investigate the redox condition of the polymer at various regions of a coating undergoing cathodically dri...
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Thin films of the polyaniline emeraldine salts of paratoluenesulphonic acid and phenylphosphonic acid have been employed to investigate the redox condition of the polymer at various regions of a coating undergoing cathodically driven delamination. Both species significantly inhibit delamination when a 0.86 mol dm{sup}(-3) NaCl electrolyte contacts a penetrative coating defect. In aerated environments, three redox states of the polymer are in evidence; namely the emeraldine salt (at intact regions), the leuco base (at the delamination front) and the emeraldine base (in the delaminated region). In the absence of oxygen, the emeraldine salt is irreversibly reduced to the leuco base during delamination. These results are consistent with the notion that the emeraldine salt of polyaniline species inhibits corrosion/delamination primarily by the suppression of through-coating O{sub}2 reduction via the ennoblement of substrate potentials.
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The present survey was conducted within the framework of MEDPOL Phase III (2004 - 2006). The purpose of the study is to provide recent information for the long-term monitoring of pollution trends in selected susceptible marine env...
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The present survey was conducted within the framework of MEDPOL Phase III (2004 - 2006). The purpose of the study is to provide recent information for the long-term monitoring of pollution trends in selected susceptible marine environments along the Mediterranean coastline. The study included the assessment of pollutants in abiotic components of the marine environment (seawater, sediment) as well as in selected marine organisms (M. barbatus and B. boops). The analysis showed low concentrations of phosphate, nitrite and ammonia and relatively high concentrations of silicate and nitrate in summer 2004. In autumn 2004 nitrite concentrations were rather low, whereas phosphate, silicate and ammonia were relatively high. Chlorophyll-a levels were high close to the Mytilini port which receives untreated sewage and low at the coastal stations in both sampling periods. Polyaromatic hydrocarbons were not detected in seawater from the port of Mytilini, with the exception of Fluοranthene in summer and Benzο-a-pyrene in autumn. Metal concentrations in sediment samples are similar to those reported for seawater bodies in Greece with no significant metal contamination. The highest metal concentrations were recorded at the station near the exit of the port of Mytilini. Statistical investigation of the data (normalization to Fe) showed a relatively mild contamination of the sediment at this station with respect to Cd, Cu, Hg, Zn and to an even lesser extent Pb. This situation may be attributed to the long-term discharge of untreated domestic effluents to the sea. Similar is the case with polyaromatic hydrocarbons, whereas halogenated hydrocarbons were not detected. Metal concentrations in the flesh of fish are similar in both species, and relatively low when compared to values in fish flesh from other areas either in Greece or in the Mediterranean, with the exception of Hg. Mercury concentrations are rather higher than those regularly reported in the literature, with the highest value found in the benthic species M. barbatus while a significantly lower value was found in the pelagic species B. bοοps. Polyaromatic and halogenated hydrocarbons were not at all detected in both pooled fish flesh samples. A general conclusion is that there is no evidence of substantial contamination in the marine environment of the eastern coast of Lesvos with respect to the pollutants analysed.
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To better understand the problem of corrosion of oxides by molten superalloys, sessile drop experiments were conducted under vacuum in a Mo-resistor furnace, followed by interfacial characterizations (SEM, EDS analyses, X-ray diff...
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To better understand the problem of corrosion of oxides by molten superalloys, sessile drop experiments were conducted under vacuum in a Mo-resistor furnace, followed by interfacial characterizations (SEM, EDS analyses, X-ray diffraction). The behavior of two Ni-base alloys A and B are compared on the basis of their contact angles on four different oxide ceramics amorphous silica, MgO stabilized zirconia, hafnium oxide and alumina. Alloys A and B have a similar composition, but only A contains Hf (1 .3 weight %). The alloy with Hf forms a HfO{sub}2 layer at the metal/ceramic interface, whereas the alloy without Hf develops an Al{sub}2O{sub}3 layer at the interface. Despite this difference, their contact angles on the four studied ceramics are quite similar. The results allow us to distinguish two kinds of wetting behavior on the four ceramics on HfO{sub}2 and Al{sub}2O{sub}3 the angles are wetting and stable, while on SiO{sub}2 and ZrO{sub}2 they decrease with time from a non-wetting value, never reaching an equilibrium angle during a one hour dwell.
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