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Number of found documents:
341
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Semantic segmentation using support vector machine classifier
Pecha, Marek; Langford, Z.; Horák, David; Tran Mills, R.
2023 - English
This paper deals with wildfire identification in the Alaska regions as a semantic segmentation task using support vector machine classifiers. Instead of colour information represented by means of BGR channels, we proceed with a normalized reflectance over 152 days so that such time series is assigned to each pixel. We compare models associated with $\mathcal{l}1$-loss and $\mathcal{l}2$-loss functions and stopping criteria based on a projected gradient and duality gap in the presented benchmarks.
Keywords:
wildfire identification; semantic segmentation; support vector machines; distributed training
Fulltext is available at external website.
Semantic segmentation using support vector machine classifier
This paper deals with wildfire identification in the Alaska regions as a semantic segmentation task using support vector machine classifiers. Instead of colour information represented by means of BGR ...
Estimation of EDZ zones in great depths by elastic-plastic models
Sysala, Stanislav
2023 - English
This contribution is devoted to modeling damage zones caused by the excavation of tunnels and boreholes (EDZ zones) in connection with the issue of deep storage of spent nuclear fuel in crystalline rocks. In particular, elastic-plastic models with Mohr-Coulomb or Hoek-Brown yield criteria are considered. Selected details of the numerical solution to the corresponding problems are mentioned. Possibilities of elastic and elastic-plastic approaches are illustrated by a numerical example.
Keywords:
tunnel stability; EDZ zones; elasto-plasticity; finite element method
Fulltext is available at external website.
Estimation of EDZ zones in great depths by elastic-plastic models
This contribution is devoted to modeling damage zones caused by the excavation of tunnels and boreholes (EDZ zones) in connection with the issue of deep storage of spent nuclear fuel in crystalline ...
Determination of the initial stress tensor from deformation of underground opening-theoretical background and applications
Malík, Josef; Kolcun, Alexej
2023 - English
In this paper a method for the detection of initial stress tensor is proposed. The method is based on measuring distances between some pairs of points located on the wall of underground opening in the excavation process. This methods is based on the solution of eighteen auxiliary problems in the theory of elasticity with force boundary conditions. The optimal location of the pairs of points on the wall of underground work is studied. The pairs must be located so that the condition number of a certain matrix has the minimal value, which guarantees a reliable estimation of initial stress tensor.
Keywords:
initial stress tensor; first boundary value problem of the theory of elasticity; condition number of matrices
Fulltext is available at external website.
Determination of the initial stress tensor from deformation of underground opening-theoretical background and applications
In this paper a method for the detection of initial stress tensor is proposed. The method is based on measuring distances between some pairs of points located on the wall of underground opening in the ...
Reduced basis solver for stochastic Galerkin formulation of Darcy flow with uncertain material parameters
Béreš, Michal
2023 - English
In this contribution, we present a solution to the stochastic Galerkin (SG) matrix equations coming from the Darcy flow problem with uncertain material coefficients in the separable form. The SG system of equations is kept in the compressed tensor form and its solution is a very challenging task. Here, we present the reduced basis (RB) method as a solver which looks for a low-rank representation of the solution. The construction of the RB consists of iterative expanding of the basis using Monte Carlo sampling. We discuss the setting of the sampling procedure and an efficient solution of multiple similar systems emerging during the sampling procedure using deflation. We conclude with a demonstration of the use of SG solution for forward uncertainty quantification.
Keywords:
stochastic Galerkin method; reduced basis method; Monte Carlo method; deflated conjugate gradient method
Fulltext is available at external website.
Reduced basis solver for stochastic Galerkin formulation of Darcy flow with uncertain material parameters
In this contribution, we present a solution to the stochastic Galerkin (SG) matrix equations coming from the Darcy flow problem with uncertain material coefficients in the separable form. The SG ...
Numerical realization of the Bayesian inversion accelerated using surrogate models
Bérešová, Simona
2023 - English
The Bayesian inversion is a natural approach to the solution of inverse problems based on uncertain observed data. The result of such an inverse problem is the posterior distribution of unknown parameters. This paper deals with the numerical realization of the Bayesian inversion focusing on problems governed by computationally expensive forward models such as numerical solutions of partial differential equations. Samples from the posterior distribution are generated using the Markov chain Monte Carlo (MCMC) methods accelerated with surrogate models. A surrogate model is understood as an approximation of the forward model which should be computationally much cheaper. The target distribution is not fully replaced by its approximation. Therefore, samples from the exact posterior distribution are provided. In addition, non-intrusive surrogate models can be updated during the sampling process resulting in an adaptive MCMC method. The use of the surrogate models significantly reduces the number of evaluations of the forward model needed for a reliable description of the posterior distribution. Described sampling procedures are implemented in the form of a Python package.
Keywords:
Bayesian inversion; delayed-acceptance Metropolis-Hastings; Markov chain Monte Carlo; surrogate model
Fulltext is available at external website.
Numerical realization of the Bayesian inversion accelerated using surrogate models
The Bayesian inversion is a natural approach to the solution of inverse problems based on uncertain observed data. The result of such an inverse problem is the posterior distribution of unknown ...
Stress state rock mass monitoring ahead of longwall No. II/501/C, Mine Staszic-Wujek, PGG, Poland -Project RFCS DD-MET
Waclawik, Petr; Kukutsch, Radovan; Staš, Lubomír; Souček, Kamil; Vavro, Leona; Vavro, Martin; Kubina, Lukáš; Schuchová, Kristýna
2022 - English
For designing precisely the reinforcement of mine gate and reinforcing underground structures in general, knowing stress and deformation states in the rock massive in the immediate vicinity of these mine works as precisely as possible is absolutely decisive. In order to verify the rock mass stress state and its changes induced by longwall mining, the monitoring of rock mass stress changing in connection with the mine out of the coal seam No. 501, longwall face No. II/501/C in the Mine Staszic-Wujek, Poland, was suggested. The aim of the contractual research was the realisation and interpretation of the rock stress state monitoring using the CCBO (Compact Conical ended Borehole Overcoring method) and CCBM (Compact Conical ended Borehole Monitoring method) probes in the forefield of mentioned longwall face within geotechnical station. To verify stress monitoring, the survey of the state of the longwall gate was carried out using a pulse 3D scanner. The purpose was to capture deformation changes ahead of the advancing longwall face, specifically, at five stages in the ± 20 m section on each side from the installed geotechnical station.
Keywords:
pre-mining stress; induced stress; 3D laser scanning
Available at various institutes of the ASCR
Stress state rock mass monitoring ahead of longwall No. II/501/C, Mine Staszic-Wujek, PGG, Poland -Project RFCS DD-MET
For designing precisely the reinforcement of mine gate and reinforcing underground structures in general, knowing stress and deformation states in the rock massive in the immediate vicinity of these ...
Structural mapping of exploration geotechnical boreholes walls within 2nd phase – Decline
Waclawik, Petr; Schuchová, Kristýna; Kukutsch, Radovan; Georgiou, Lucie
2022 - English
Structural-geological analysis, i.e. fracturing assessment of the walls of geotechnical boreholes (CIS38 and CIS39) within the projected Decline in lithium exploratory area was carried out on the basis of optical (OPTV) and acoustic televiewer (HiRAT) records evaluation. HiRAT and OPTV probes are part of the Robertson Geologging logging equipment. The apparatus has an electric winch with a four core logging cable, which transmits the data recorded by the probes via a data logger to a computer. The spatial data obtained from interpretation of the geotechnical boreholes records were structurally analysed. The submitted research report comprehensively summarises the findings obtained from the structural mapping of geotechnical boreholes. On the basis measured data the rock mass quality evaluation of boreholes walls were additionally done. The complex data have been allowed very precise analysis of rock mass structural conditions, which are necessary for design of opening mine working.
Keywords:
geotechnical boreholes; structural mapping; geotechnics
Available on request at various institutes of the ASCR
Structural mapping of exploration geotechnical boreholes walls within 2nd phase – Decline
Structural-geological analysis, i.e. fracturing assessment of the walls of geotechnical boreholes (CIS38 and CIS39) within the projected Decline in lithium exploratory area was carried out on the ...
Viewpoint geosites and their potential for geoeducation and geotourism
Kubalíková, Lucie; Kirchner, Karel; Kuda, František
2022 - English
Viewpoint geosites are locations which allow observation of the surrounding landscape and comprehension of geodiversity (or Earth history recorded in rocks, structures and landforms) visible from this locality. The sites themselves don‘t have to be attractive from the Earth-sciences point of view, so they may be both natural (e.g. rock outcrops, mountain tops) and man-made objects (e.g. watchtowers, view terraces). These sites represent a very important resource for geotourism and geoeducation as they allow understand landscape, its history and relationships between its components. In this paper, we present examples of viewpoints from Podyjí National Park (both natural and man-made structures) that allow to observe geodiversity of the area. For an effective management and rational use of these specific and important sites, it is necessary to identify their characteristics and potential, so the guidelines for inventorying and method for assessment their potential are proposed. These procedures can contribute to the development of geotourist and geoeducational activities and above all, they enable better understanding of geodiversity’s position within landscape and justify its conservation and sustainable use.
Keywords:
geodiversity; inventory; assessment; landscape; viewshade analysis
Fulltext is available at external website.
Viewpoint geosites and their potential for geoeducation and geotourism
Viewpoint geosites are locations which allow observation of the surrounding landscape and comprehension of geodiversity (or Earth history recorded in rocks, structures and landforms) visible from this ...
Landscape photography in the research of landscape change
Skokanová, H.; Halas, Petr; Koutecký, T.; Kallabová, Eva; Havlíček, M.; Slach, T.
2022 - English
The paper presents partial results of “entering” landscape photography, which can be considered as a complementary method for the research of landscape changes. Unlike the usual assessment of landscape changes using cartographic and other archival sources, old landscape photographs can contribute to the deeper knowledge of the local specifics of the examined places or supplement the conventional procedures. Thanks to the ongoing project, supported by the Technology Agency of the Czech Republic (TL02000222), we documented changes in photographic shots of various landscapes in the 20th century. We also added information about environment, vegetation, and geography and photo documentation of the details of the researched shot. This creates a comprehensive output for each old landscape photograph. Such processed photographs have been presented at exhibitions in museums and galleries. Furthermore, they will be available to municipalities and public at a web page created as a tool to support public recreation. Here we present some examples from the Bohemian-Moravian Highlands. They show four types of landscape changes: 1) afforestation and overgrowth bywoody vegetation, 2) changes in the agricultural landscape, 3) loss of the grazing landscape, and 4) changes related to watercourses.\n
Keywords:
photographic shots; landscape structure changes; Bohemian-Moravian Highlands; vegetation change; public recreation
Fulltext is available at external website.
Landscape photography in the research of landscape change
The paper presents partial results of “entering” landscape photography, which can be considered as a complementary method for the research of landscape changes. Unlike the usual assessment of ...
Structural mapping of exploration geotechnical boreholes walls within 1st phase – Ore Zone
Waclawik, Petr; Vavro, Martin; Schuchová, Kristýna; Kukutsch, Radovan; Staš, Lubomír; Souček, Kamil; Georgiou, Lucie
2021 - English
Structural-geological analysis, i.e. fracturing assessment of the walls of geotechnical boreholes (CIS12, CIS14, CIS31 and CIS37) within the Ore Zone lithium exploratory area was carried out on the basis of optical (OPTV) and acoustic televiewer (HiRAT) records evaluation. HiRAT and OPTV probes are part of the Robertson Geologging logging equipment. The apparatus has an electric winch with a four-core logging cable, which transmits the data recorded by the probes via a data logger to a computer. The spatial data obtained from interpretation of the geotechnical boreholes records were structurally analysed. The submitted research report comprehensively summarises the findings obtained from the structural mapping of geotechnical boreholes. On the basis measured data the rock mass quality evaluation of boreholes walls were additionally done. The complex data have been allowed very precise analysis of rock mass structural conditions, which are necessary for construction geomechanical model.
Keywords:
geotechnical boreholes; structural mapping; rock mass quality
Available at various institutes of the ASCR
Structural mapping of exploration geotechnical boreholes walls within 1st phase – Ore Zone
Structural-geological analysis, i.e. fracturing assessment of the walls of geotechnical boreholes (CIS12, CIS14, CIS31 and CIS37) within the Ore Zone lithium exploratory area was carried out on the ...
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