Yes (180)
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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 ...
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 ...
Vývoj nástrojů pro minimalizaci rizik kontaminace ovzduší respirabilními azbestovými vlákny uvolňovanými lidskou činností z horninového prostředí – souhrnná výzkumná zpráva o průběhu a výsledcích řešení projektu
Vavro, Leona; Vavro, Martin; Daněk, T.; Kajzar, Vlastimil; Drozdová, J.; Raclavský, K.; Kubina, Lukáš
2023 - Czech
Souhrnná výzkumná zpráva přináší zhodnocení postupu a výsledků projektu SS01010257 - Vývoj nástrojů pro minimalizaci rizika kontaminace ovzduší respirabilními azbestovými vlákny uvolňovanými lidskou činností z horninového prostředí (AZROCK). Řešený projekt měl dva hlavní cíle. Prvním bylo vytvoření dvou metodických návodů, a to jednak pro odběr vzorků hornin a kameniva s možným obsahem přirozeně se vyskytujících azbestů a jednak pro následnou analýzu přítomnosti azbestových vláken v odebraných vzorcích. Dále si projekt stanovil za cíl tvorbu specializované mapy rizika výskytu azbestu v horninovém prostředí v České republice a internetového znalostního portálu azbestů. Podstatná část řešení projektu byla založena na odběru vzorků hornin a kameniva na téměř stovce vytipovaných lokalit po celé České republice a jejich následném vyhodnocení zvoleným a ověřeným souborem analytických metod. Podobné informace o výskytu azbestu v horninovém prostředí České republiky nebyly dosud zájemcům z řad odborné i laické veřejnosti k dispozici. The summary research report provides an evaluation of the procedure and results of the project SS01010257 - Development of tools to minimise the risks of air contamination by respirable asbestos fibres released from the rock environment by human activities (AZROCK). The solved project had two main objectives. The first one was the creation of two methodical instructions, both for the rock and aggregate sampling with a possible naturally occurring asbestos content and for the subsequent analysis of the presence of asbestos fibers in the samples taken. Furthermore, the project set itself the goal of creating: (1) a specialized map of the risk of asbestos occurrence in the rock environment in the Czech Republic and (2) a web knowledge portal of asbestos. A substantial part of the project solution was based on the collection of samples of rocks and aggregates at almost a hundred selected sites throughout the Czech Republic and their subsequent evaluation using a selected and verified set of analytical methods. Similar information on the occurrence of asbestos in the rock environment of the Czech Republic has not yet been available to interested professionals and the non-specialist public.
Keywords:
naturally occuring asbestos; rocks; aggregate; sampling; analysis; Czech Republic
Fulltext is available at external website.
Vývoj nástrojů pro minimalizaci rizik kontaminace ovzduší respirabilními azbestovými vlákny uvolňovanými lidskou činností z horninového prostředí – souhrnná výzkumná zpráva o průběhu a výsledcích řešení projektu
Souhrnná výzkumná zpráva přináší zhodnocení postupu a výsledků projektu SS01010257 - Vývoj nástrojů pro minimalizaci rizika kontaminace ovzduší respirabilními azbestovými vlákny uvolňovanými lidskou ...
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 ...
Metodika určování provenience zdrojových surovin pro výrobu historických vápenných malt
Martinec, Petr; Ščučka, Jiří
2022 - Czech
Metodika byla vypracována v letech 2018-2021 v rámci řešení projektu NAKI II č. DG18P02OVV017 s názvem Historická krajina na pomezí Slezska a Moravy financovaného Ministerstvem kultury ČR. Metodika vychází z dlouholetých zkušeností prof. Ing. Petra Martince, CSc. a doc. Ing. Jiřího Ščučky, Ph.D. v oblasti geomateriálových a stavebně-materiálových analýz, které jsou prováděny v Ústavu geoniky AV ČR, v. v. i. ve spolupráci s odborníky z oborů archeologie a památkové péče. Metodika obsahuje komplexní postup při identifikaci potenciálních původních zdrojů surovin použitých pro výrobu hlavních materiálových komponent historických vápenných malt – kameniva a pojiva. Součástí metodiky jsou zásady odběru vzorků malt a srovnávacích horninových či zeminových vzorků in situ, postupy laboratorní materiálové analýzy kameniva, pojiva a hornin pro určení rozhodných srovnávacích parametrů, a také hlavní informační zdroje, z nichž lze při hledání surovinových zdrojů vycházet. The methodology was developed in the years 2018-2021 as part of the solution of the project Historical landscape on the border of Silesia and Moravia financed by the Ministry of Culture of the Czech Republic (project No. DG18P02OVV017, NAKI II programme). The methodology is based on the long-term experience of prof. Petr Martinec, Ph.D. and Jiří Ščučka, Ph.D. in the field of geomaterial and building material analyses, which are carried out at the Institute of Geonics of the Academy of Sciences of the Czech Republic in cooperation with experts from the fields of archaeology and monument care. The methodology includes a comprehensive procedure for identifying potential original sources of raw materials used for the production of the main material components of historical lime mortars – aggregate and binder. The methodology also includes: principles of sampling mortars and comparative rocks or soils in situ, procedures for laboratory material analysis of aggregates, binders and rocks to determine relevant comparative parameters, and the main information sources that can be used when searching for sources of raw materials.\n
Keywords:
lime mortar; aggregate; binder; source of raw materials; archaeology; monument care
Available in a digital repository NRGL
Metodika určování provenience zdrojových surovin pro výrobu historických vápenných malt
Metodika byla vypracována v letech 2018-2021 v rámci řešení projektu NAKI II č. DG18P02OVV017 s názvem Historická krajina na pomezí Slezska a Moravy financovaného Ministerstvem kultury ČR. Metodika ...
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 ...
Polycentric urban forms: The relevance of scale for metropolitan and city planning
Malý, Jiří; Krejčí, Tomáš
2021 - English
The paper deals with the importance of scale in metropolitan and urban planning, in connection with the promoted and often applied concept of polycentric development. Although the normative conceptualization of polycentricity to some extent reflects the multi-scalar dimension, the operationalization of the concept encounters a number of limitations and fuzzy meanings that result from different scales of analysis and interpretation. Using the Czech context of planning practice, the negligence of the importance of overlapping geographical scales and limits of binding spatial planning materials is documented. The dependence of polycentricity on the scale has consequences both for the analytical evaluation of the spatial situation of the settlement system and for the subsequent interpretation of the results and the setting of further development strategies.\n
Keywords:
polycentricity; scale; metropolitan planning; urban planning
Fulltext is available at external website.
Polycentric urban forms: The relevance of scale for metropolitan and city planning
The paper deals with the importance of scale in metropolitan and urban planning, in connection with the promoted and often applied concept of polycentric development. Although the normative ...
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