The article explores using very high-resolution RGB data from unmanned aerial vehicles (UAVs) to explore the possibilities of utilizing data to monitor vegetation. The Baroch nature reserve, located in the Pardubice region of the Czech Republic, is used as an area of interest. Data is collected using the UAV DJI Mavic 2 DUAL Enterprise. The reserve is overgrown mainly with reed and cattail and is used as a pasture. The paper aims to determine the effectiveness of utilizing UAV technology and very high-resolution RGB data to identify, monitor, and classify vegetation types in this grassy habitat and to provide insights into the practicality of using such data for ecological research and landscape management purposes.
The study aims to evaluate the Landsat 8 Thermal Infrared Sensor land surface temperature (LST) products and Visible Infrared Imager Radiometer Suite (VIIRS) LST environmental data record against ground observations in Armenia and Belarus. The data from the Landsat-8 satellite is used due to its high spatial resolution. In contrast, the VIIRS information is obtained due to its high temporal resolution, accessible with a minimal delay after the flyby of satellites. Algorithms to calculate LST were analyzed to find the best performance for both daytime and nighttime data. The evaluation shows that the current VIIRS LST products demonstrate a reasonable accuracy, with a root mean squared error average of 2.77 $\mathbf{K}$ and an average coefficient of determination of 0.92 K.
This paper deals with the exploration of a system which acts on demand in case of emergency matter. To verify functionality, each component of the system must be regularly inspected with a specified inspection interval and tested to find latent failures. A failure-based preventive maintenance (PM) is considered, in context with the imperfect corrective maintenance model. This means that PM brings full renew which is realized after a beforehand setting the number of failures. If a failure occurs, it is detected during the first follow-up inspection and the reparation process starts. The imperfect corrective maintenance model is intended where each repair deteriorates the system life-time whose probability distribution is gradually altered through rising failure rate. Reliability mathematics for unavailability analysis is briefly demonstrated. The new renewal process model, including the failure-based PM, has been termed as a real ageing process. The imperfect corrective maintenance as well as increasing length of the inspection interval result in unwanted increase of system unavailability function which can be eliminated as well as optimized by the properly selected failure-based PM applied to all system components. If the PM is fixed due to cost, inspection intervals of system components can be optimized to keep the maximal value of the unavailability function in its original level. Sensitivity analysis applied to the length of the optimal inspection intervals with regard to gradually changing PM is demonstrated. This optimization process is demonstrated on a four-component system adopted from references.
This paper uses a novel method for evaluating land degradation in mountain-protected reserve areas based on remotely-sensed data. A risk map is developed based on this method for the investigated area. The risk is computed based on quantifying drivers of land degradation that can be estimated remotely. This paper considers terrain slope, vegetation cover, and surface soil moisture (SSM) as drivers. The risk value for developing a risk map is computed, which should be from one of the indicated classes (typically, the number of classes is from three to five). Therefore, the threshold for risk should be introduced to indicate the risk class on the map. The Slovakian National Park of Pieniny is chosen as the study area. The data for the investigation has been obtained from the European remote sensing satellite system Copernicus Sentinel. The terrain slopes have been extracted from a digital surface model (DSM), which in turn was obtained from an interferometric pair of radar images of the Sentinel-1. The vegetation cover has been indicated by the leaf area index (LAI). LAI maps can be derived from optical Sentinel-2 satellite imagery and radar Sentinel-1, The specifics of this study and the presented result are the use of a short time series of Sentinel-2 multispectral images formed, acquired annually under the same phenological conditions - during the late June to early July period. Analysis of the risk map allows determining the terrain slope as the most significant driver of land degradation, which, moreover, has not changed much for decades. Vegetation cover acts as an additional land-strengthening agent. The SSM impact could not be disclosed, possibly due to small statistics and insufficient spatial resolution.
In recent decades, a significant increase in the share of renewable energy sources in power grids at various voltage levels has been observed. A number of articles have been published highlighting emerging problems in low-voltage grids with a large share of prosumers and in medium- and high-voltage grids to which photovoltaic (PV) plants are connected. The article analyzes the medium-voltage grid in terms of the possibility of connecting maximum PV power to it, while maintaining the criterion of the proper voltage level in the whole grid. The selection of suitable locations for PV power plants is analyzed, as well as the expected effect of the possible modernization of the grid - replacement of the main line with lines having a larger cross-section. As a result of the analysis, the percentage profits from both presented solutions (PV power plants optimal locations and main power line modernization) have been compared.
