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1

Optimal selection of numerical models for flood embankment pore pressure and temperature data

Chuchro M., Dwornik M., Szostek K., Leśniak A.

Computer Science

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2017

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Vol. 18 (4)

399--412

EN

The aim of the ISMOP project is to study processes in earthen flood embankments: water filtration, pore pressure changes, and temperature changes due to varying water levels in the riverbed. Developing a system for continuous monitoring of flood embankment stability is the main goal of this project. A full-size earthen flood embankment with built-in sensors was built in Czernichow and used to conduct experiments involving the simulation of different flood waves, with parameters mostly measured at time intervals of 15 minutes. Numerical modelling—in addition to providing information about phenomena occurring in the embankment due to external factors and changes in water level—could be used to assess the state of the embankment. Modelling was performed using Itasca Flac 2D 7.0 with an assumed grid cell size of 10x10 cm. The water level in the embankment simulated the water flow in the Wisła River and the temperature of the air and water. Data about the state of the flood embankment was exported every hour. Using numerical models and real experiment data, a model-driven module was used to perform comparisons. Analyses of each half-section of the flood embankment were carried out separately using similarity measures and an aggregate window. For the tests, the North-West (NW) half cross-section of the embankment was chosen, which contains pore pressure and temperature sensors UT6 to UT10. The water level in the embankment was raised to a height of 3m; the best numerical model was considered the one that best matched the actual data recorded by the sensors during the experiment. The experiment period was from 9pm on 29/08/2016 to 9am on 03/09/2016. Seventeen numerical models of the water level rising to 2, 3, and 4 meters were compared against real experimental data from the NW half cross-section. The first step was to verify the similarity between the incoming data from the sensors. If the correlation value exceeded 0.8, the data from the sensors was averaged. The experimental data was then compared against the numerical models using least absolute deviations L1-Norm. The L1-Norm varied from 26 to 32, depending on window length and the numerical model used.

2

Influence of initial water saturation in earthen levees on results of numerical modelling of infiltration processes

Dwornik M., Franczyk A., Leśniak A., Krawiec K.

Computer Science

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2017

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Vol. 18 (4)

413--427

EN

Levees in Poland are mostly earthen constructions. The stability of earthen levees depends largely on factors such as the construction material, meteorological conditions and natural elements. The influence of initial water saturation of pore space on levee stability is analysed in this paper. Analysis was performed using numerical modelling and water pore pressure results were compared against data obtained from sensors located in a levee. The numerical modelling shows the moderate influence of initial water level on distribution of water pore pressure during high water level.

3

Analysis of annual temperature distribution inside the experimental embankment

Bukowska-Belniak B., Dwornik M., Leśniak A.

Computer Science

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2017

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Vol. 18 (4)

385--397

EN

The aim of this paper is analysis of temperatures distribution inside experimental embankment from August 2015 to September 2016. Analysis was carried out in order to interpretation of the results of the flood experiments performed on the experimental embankment. The reference for year temperature changes in the embankment at various depths was obtained. A simplified model of temperature changes depending on the depth was made. The model parameters which can be used for modelling the temperatures in the embankment during the experiments were estimated.

4

How fluids infiltrate through fractures and change metamorphic rocks – a case study from northern Spitsbergen

Faehnrich K., Kośmińska K., Majka J., Dwornik M.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

69--70

EN

Metasomatism is a process leading to changes in the chemical composition of a rock or its portion. It involves introduction or removal of chemical components due to the interaction of the rock with aqueous fluid (Zharikov et al. 2007). Here we present a case study of metasomatic changes in metapelites from northern Spitsbergen. There is a visible metasomatic zonation in the studied samples. The most intense changes are observed close to the contact with fractures, whereas the zones farther away from them are less altered or not affected by fluids at all. Thin sections were prepared from all of the aforementioned zones. The mineral chemistry was obtained using a JEOL SuperProbe 8230 electron microprobe at Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology. Mineral assemblage varies from Grt-Bt-Qtz-Pl in zones that were not affected by fluids to Grt- Chl-Bt-Qtz-Pl in altered portions of the rock. Garnet forms subhedral crystals with abundant quartz inclusions. Its composition is changing from Alm 0.56 Sps 0.11 Prp 0.05 Grs 0.28 in the core to Alm 0.64 Sps 0.03 Prp 0.09 Grs 0.24 in the rim. It shows bell-shaped Sps profile and opposite Alm trend, indicating one-step progressive garnet growth. Plagioclase composition is characterized by Ab 74.16 An 24.39 Or 1.44 , K-feldspar also occurs along with Fe-chlorite. Point counting technique was used to estimate volume percentage of minerals. For each thin section one thousand points were counted. Plagioclase, quartz and biotite are the main phases, building more than 95% of the rocks. The amount of garnet oscillates around 2% and chlorite varies from 2.38% to 0%. Point counting technique was compared with image analysis, which was performed using the Matlab software. The image analysis revealed that the amount of biotite is changing in different zones from 35.42% to 37.38%, whereas chlorite from 1.54% to 0%, respectively. The redistribution of elements between biotite and chlorite was investigated by volume and mass-balance using Gresens (1967) approach. During chloritization of biotite amount of H 2 O in the system must have increased by ca. 8% in order to form 2.4% chlorite. Potassium released during this reaction was bonded to secondary K-feldspar, which is apparent on BSE images, and it is closely associated with biotite and chlorite. This study reveals that metasomatic zones significantly differ in mineralogical composition and fluid-induced alterations are more pervasive closer to the fractures. It has also been concluded that replacement of biotite by chlorite required aqueous fluids, with inflow and outflow of metallic ions and formation of K-feldspar as a product of biotite breakdown reaction. Further investigations will involve X-ray mapping using the XMap Tools software in order to obtain more in depth information on volume of minerals and their chemistry. Pressure and temperature conditions of metamorphism will be determined using garnet-biotite geothermometry and thermodynamic modelling. Isocon method will be used to track changes in whole rock chemistry due to interaction with fluid (Grant 1986, 2005).

5

Analysis of stability levee during different flooding wave stages

Dwornik M., Franczyk A.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

67--68

EN

The stability of levee depends mainly on mechanical and hydromechanical properties of material used for its construction. The structural capacity of a system beyond the expected loads or actual loads is calculated to a variety of different underground structures such as slopes, retaining walls or tunnels. The stability of structure is often expressed by Factor of Stability (FoS) obtained by numerical modeling. In case of the stability analysis of the levee, the flooding process is limited to few scenarios of flooding waves. The first approach of determination of the most significant stages of flooding wave shape can be found in Dwornik et al. (2015). In this paper, the stability of earthen levee for different stages and flooding waves was calculated. Stability of the levee was described using Factor of Safety implemented in Itasca Flac 2D 7.0 software using the strength reduction procedure (Itasca 2011). It is applied by a strength reduction method, which reduces the shear strength of the material to bring the slope to a state of limiting equilibrium. The value of FoS bigger than 1.0 indicate the stable construction, whereas the value less than 1.0 should be interpreted as a possible unstable model (Itasca 2011). Numerical modeling presented in this paper was performed for 17 different schemes of flooding wave. All the schemas were slight modification of the flooding wave considered during the ISMOP project (www.ismop.pl, Mościcki et al. 2014). The analysis was conducted to the flooding wave described by the four stages: water level increasing, durability of the height water level, the pace of water level decreasing and durability of the stage between cycles of successive flooding waves. The increasing of the water level assumed in the numerical modeling varied from 0.1 m to 3.5 m in height. The high water level, assumed as a 3.5 m, was different for the individual scenario. The decreasing water level varied from 3.5 m to 0.1 m preceding the low water level assumed 0.1 m in height. Calculations show that levee is stable for all tested construction stages. The lowest FoS value was obtained after decreasing water level in the reservoir between levees. The slowest pace of decreasing water level was assumed, the higher value of FoS was obtain, which indicated better levee stability. The study was partly financed from the statutory research project No. 11.11.140.613 of the Department of Geoinformatics and Applied Computer Science, AGH University of Science and Technology and by the National Centre for Research and Development (NCBiR) in Poland, project PBS1/B9/18/2013 (no 180535).

6

A Big Data processing strategy for hybrid interpretation of flood embankment multisensor data

Chuchro M., Franczyk A., Dwornik M., Leśniak A.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 3

269--277

EN

The assessment of flood embankments is a key component of a country’s comprehensive flood protection. Proper and early information on the possible instability of a flood embankment can make it possible to take preventative action. The assessment method proposed by the ISMOP project is based on a strategy of processing huge data sets (Big Data). The detection of flood embankment anomalies can take two analysis paths. The first involves the computation of numerical models and comparing them with real data measured on a flood embankment. This is the path of model-driven analysis. The second solution is data-driven, meaning time series are analysed in order to detect deviations from average values. Flood embankments are assessed based on the results of model-driven and data-driven analyses and information from preprocessing. An alarm is triggered if a critical value is exceeded in one or both paths of analysis. Tests on synthetic data demonstrate the high efficiency of the chosen methods for assessing the state of flood embankments.

7

Wpływ metod analiz na niepewność oznaczeń chlorowców w wodach powierzchniowych zlewni górnej Odry i w wodach kopalnianych do niej odprowadzanych

Dwornik M., Kmiecik E., Bebek M.

Przegląd Geologiczny

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2015

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Vol. 63, nr 10/1

705--709

EN

In this paper the total uncertainty and its components (geochemical, sampling and analytical) were assessed with use of the empirical approach. For uncertainty estimation there were used results from analyses of normal and control (duplicate) samples, which were collected within monitoring of Upper Odra River Basin surface water and coalmine water inducted to it. Moreover, the influence of analyses method on the measurement uncertainty was examined. Results of ICP-MS, IC and titration methods were compared. The assessment of total uncertainty and its components was shown on the example of halogens (Cl −, Br − and I −) results delivered from normal and duplicate samples analyses.

8

A 2D Model of Temperature Changes in Experimental Embankment

Bukowska-Belniak B., Dwornik M., Pięta A., Leśniak A.

Measurement Automation Monitoring

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2015

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Vol. 61, No. 6

233--236

EN

The paper presents the results of experimental embankment 2D thermal modeling. The main purpose of modeling was to investigate the influence of air temperature on temperature distribution in such soil structure. Modeling was performed on an oval experimental embankment with the tank in the inter-embankment part. Modeling assumes flooding and discharging the tank, with maximum water level equal to 3.5 m. 2D model was realized using FLAC 7.0 software, which is a two-dimensional explicit finite difference program for engineering mechanics computation. The results of modeling show extent of temperature changes an impact of variable-time air temperature and water temperature.

9

Influence of resolution in spatial and time for numerical modeling of levees

Dwornik M., Pięta A.

Geology, Geophysics and Environment

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2015

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Vol. 41, no. 1

71--72

EN

Stability of geotechnical constructions, such as levees, is one of the most important issues for urban areas. The precise prediction of levees destruction during the f lood can not only save human lives and properties, but also protect the natural environment (Krzhizhanovskaya et al. 2011). During ISMOP project (Computer System for Monitoring River Embankments), an artificial levee will be built and monitored using dense grid of sensors, mainly thermal and pore pressure ones. Planned levee will be an enclosed region with the water inside embankments. This construction will be placed in Czernichów near Kraków (Poland), close to existing Vistula River embankment (ISMOP 2014). The main aim of the project is to create a remote system, which can inform about possibility of losing levee stability. Water level changes and its inf luence on the stability of levee was preceded by 2D and 3D numerical modeling, conducted in Itasca Flac software (Itasca 2011) based on finite-difference method. The modeling of levee behavior at various water levels (simulation of the flood waves) allow to select appropriate scenarios for real experiments and indicate the optimal location of sensors. It is important, because only limited number of scenarios can be performed in real conditions.The first step included several 2D numerical modelings performed to obtain relevant shape and size of grid cells and offset of boundary condition (Bukowska & Krawiec 2014, Pięta & Dwornik 2014) for mechanical and fluid calculation. Numerical modeling for both thermal and dynamic analysis force using regular computational grid with smaller size of computational cells than the cell used for fluid modeling. Other specifications (adaptive shape or bigger than 0.1m cell size) caused instability in calculation of thermal fields. It also determines the depth of computational model in order to preserve natural exchange temperature between air, soil and water. Another problem was time step of modeling. Too short time step cause in a huge number of data, increasing calculation time and could make some calculations unstable or incorrect. Too long time step can cause incorrect prediction of destruction model and inadequately simulate natural phenomena of dynamic processes. Results obtained for 2D mechanical modeling were confirmed with 3D modeling of full levee and geological background. The lack of other processes in 3D modeling was caused by very long time of modeling the fluid-soil interaction. Results of two dimensional numerical modeling shows, that 2D modelling can be regarded as a powerful and sufficient tool to estimate the stability of levee. The optimal size of grid and time step can make this calculation more efficient.

10

Welcome in Herlandia 2014 XVth International Conference of Young Geologists Her'lany 2014 Międzybrodzie Żywieckie, Poland, May, 8th-10th 2014

Dwornik M., Manecki M., Zahradnikova B., Kovacova M., Zahradnik L., Greganova M., Kondela J., Strba L., Vizi L., Bazarnik J., Majka J., Kwaśniak-Kominek M., Kośmińska K.

Geology, Geophysics and Environment

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2014

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Vol. 40, no. 1

77

EN

The 15th International Conference of Young Geologists was held in the Polish Outer Carpathians, in Międzybrodzie Żywieckie, located in the Beskid Mały Mts. All participants were hosted in Niagara resort. The conference was organized by the AGH University of Sciences and Technology (AGH), Krakow (PL), Faculty of Natural Sciences of Comenius University (CU), Bratislava (SK) and the Faculty BERG of Technical University (TUKE), Kosice (SK). For several years the members of the scientific committee have been Prof. Dusan Plasienka (CU), Julian Kondela (TUKE) and Prof. Maciej Manecki (AGH). The conference was organized by Ph.D. students from AGH and the members of the Geological Club from Bratislava. This year 70 young scientists from Poland, Slovakia, Czech Republic and Russia participated in the conference. They presented over 50 talks covering a very wide spectrum of Earth science disciplines such as: tectonics, sedimentology, mineralogy, petrology, paleontology, geophysics, geoengineering and geoinformatics. The best student presentation in English was awarded with the Rudolf Mock Award. This year, the award went to Karolina Kośmińska, Ph.D. student from AGH, for excellent presentation in petrology on blueschists from Svalbard. The award was presented during closing ceremony by Professor Maciej Manecki. An important part of the meeting was "evening dinner discussion", where Professor Jan Golonka (AGH) presented his lecture on evolution of the Outer Carpathians. Topic of the lecture was also an introduction to the geological excursion. On Saturday, the participants visited pumped-storage hydroelectric power plant in Porąbka and unique outcrops of cieszynity in Cieszyn area. A guided tour in Brewery Museum in Żywiec ended the excursion. The next conference will return to the original location, Her'lany, Slovakia.

11

Porównanie metod redukcji szumu dla środowiskowych obrazów termograficznych

Bukowska-Belniak B., Dwornik M., Leśniak A.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 9

994--997

PL

W artykule przedstawione zostały standardowe oraz nowoczesne metody redukcji szumu dla termograficznych obrazów cyfrowych. Pokazano działanie kilku rodzajów filtracji różniących się zasadą działania: począwszy od metod działających w domenie przestrzeni lub częstotliwości do metod przestrzenno-częstotliwościowych (transformata falkowa, krzywkowa). Metody odszumiania przetestowane zostały zarówno na przykładzie temperaturowych obrazów syntetycznych, jak i na rzeczywistych środowiskowych obrazach termicznych.

EN

Thermography, as a fast and remote method of temperature imaging, can be used in environmental process monitoring [1, 2]. The recorded thermal images are noisy and low contrast. In Section 2 of the paper standard and modern methods of noise reduction for digital images are presented. The effect of several different types of filtration (operations in space or frequency domain [5, 6, 7]) and spatial-frequency transforms (wavelet transform (Fg. 1) [8] and curvelet transform [9]) are shown in Section 3. Noise reduction methods were tested both on synthetic temperature data examples and environmental thermal images. In order to examine the noise level of a camera, after the camera software corrections, the experiment (Fig. 2) was conducted. Fig. 3 shows the results of synthetic image denoising. Tab. 1 lists the mean square error for all the presented methods. In Section 4 the results of all the noise reduction methods for environmental images are presented (Figs. 4, 5). The best results for synthetic images were obtained for the wavelet transform using Daubechies wavelet family. This method required adapting several parameters. For both environmental images the Butterworth filtering, the wavelet and curvelet methods gave the bests results.

12

Tectonics of the Chęciny Anticline (Holy Cross Mts., central Poland) in the light of new cartographic data and calcite vein analysis (discussion)

Mastella L., Konon A., Dwornik M., Ludwiniak M., Rybak-Ostrowska B., Śmigielski M.

Geological Quarterly

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2013

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Vol. 57, No. 1

175–-180

13

Parallel Implementation of Ray Tracing Procedure in Anisotropic Medium

Pieta A., Dwornik M.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2012

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Vol. 16, No 1-2

135-143

EN

This article describes a parallel implementation of a ray tracing algorithm in a heterogeneous anisotropic geological medium. The shortest path method, which was used for calculations, can give ray path and travel time of seismic wave propagation even for a random and discontinuous velocity field. The high precision required in such calculations was obtained by employing a dense computational grid. This led to a significant increase in the computational effort of the algorithm. The procedure was parallelized using domain decomposition. The results show that the parallel performance of the ray tracing procedure strongly depends on the assumed geological method and differs between media with and without anisotropy of seismic wave propagation.

14

Welcome in Herlandia 2013 XIV International Conference of Young Geologists Herl'any 2013 Svaty Jur, Slovak Republic; 4-6 April 2013

Zahradnikova B., Greganova M., Zahradnik L., Kovacova M., Strba L., Vizi L., Majka J., Dwornik M., Bazarnik J.

Geology, Geophysics and Environment

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2012

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Vol. 38, no. 4

451--452

EN

The XIV International conference of young geologists was organized in Svaty Jur near Bratislava from 4 to 6 April 2013. Conference was traditionally organised by members of Geological Club in Bratislava and by team from AGH University of Sciences and Technology in Krakow and Faculty BERG of Technical University in Kosice. Scientific guarantee of the conference this year took over Prof. Dusan Plasienka from Faculty of Natural Sciences, Comenius University in Bratislava (SK), Prof. Maciej Manecki from AGH, University of Sciences and Technology in Krakow (PL) and Dr. Julian Kondela from Faculty BERG of Technical University in Kosice (SR).

15

Inversion of seismic tomography data by Metropolis and simulated annealing algorithm

Dwornik M.

Geology, Geophysics and Environment

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2012

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Vol. 38, no. 4

463--464

EN

Inversion of seismic tomography is non-uniqueness and bad-conditioned problem. Reconstruction of velocity field is a process of minimization error function between estimated and received travel times. Classical, deterministic method, like matrix decomposition or conjugate gradient, is known for finish calculation in local minimums. Other problems with deterministic methods were application of constraints to the solution. Stochastic algorithms are methods that can be helpful in solving inverse problem in seismic tomography. This paper presents application of the following two stochastic algorithms to reconstruct velocity field: Metropolis algorithm (MA) and simulated algorithm (SA). The Metropolis algorithm is an iterative method and it was first described by Metropolis et al. (1953). This method uses Boltzmann distribution to calculate probability of replacing current solution by worse one, which is modification of current. Level of acceptance is given by value of a temperature. The simulated annealing was first described by Kirkpatrick et al. (1983) and it is a modification of Metropolis algorithm. This algorithm decreased temperature during iterative process. Both algorithms were modified by adding two dimensional median filtration in a place of modification of current velocity field. This filtration was applied with some small probability. Estimation of travel times of primary seismic waves was performed using two ray-based methods: a straight line and a shortest path method (Moser 1991, Pięta & Dwornik 2009). The first method was very fast but nonrealistic in heterogeneous geological medium. The second method had over one hundred times longer calculation time, but provided real ray trajectories. The algorithms were tested in series by ten independent numerical simulations for each parameter of configuration to minimize random effects of stochastic methods. Both algorithms were initialized in two ways: by random velocity fields and by velocity field obtained by SIRT algorithm (Lo & Inderwiesen 1994). Application of median filtration and initializing by SIRT solution decreased calculation time and improved quality of inversion.

16

Cellular automata for seismic travel time estimation

Szostek K., Dwornik M.

Geology, Geophysics and Environment

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2012

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Vol. 38, no. 4

541--542

EN

In this work, the application of the cellular automata for the seismic first breaks time estimation is presented. Cellular automata (CA) algorithms are usually described by set of simple rules applied onto the grid of cells, which can represent one of the few different discrete states. In spite of this simplicity, these algorithms can still simulate variety of complex physical processes, i.e. model the fluids or gases behavior, but also simulate and predict forests fire or the spread of diseases (Turcotte 1997). What is more, these algorithms are easy to accelerate using one of the most advanced parallelization techniques, like graphics card programming - the calculation can be then performed even 1000 times faster. In this work one of the popular CA, presented by Hardy et al. (1973), was modified, according to Rothman (1987), to perform the simulation of the seismic wave propagation in geological medium. This CA was initially designed to simulate gas behavior in a reservoir, but it was modified in the following way: each cell of the grid contains set of values, which represents particles - positive and negative - that describes expansion and compression, respectively, of that cell. Then, both particle sets are calculated separately in two steps: the first is the propagation, when each particle is moved to next cell according to its movement; the second is collision, when rules are applied on each particle, if there is more than one particle in the cell. The collision rules can be divided into categories that represent their complexity, i.e. more complex behavior can be achieved if static particles are implemented, but this requires additional rules of collisions with moving particles. All the rules have to preserve the principle of conservation of mass and momentum. The major modification of the algorithm described by Rothman (1987) is the implementation of the Boltzmann lattice method (Huang 2007), which changes the regular rectangular cellular grid for the triangular network. This modification provides more option when implementing algorithm, especially the collisions rules. On the one hand, triangular grid requires slightly different approach to represent it in computer memory, just like the implementations of the rules. On the other hand, triangular grid can produce better simulation results compared to the classical rectangular grid. The results of this simulation can be used in further calculations, i.e. to solve the inverse problem. To make this CA useful, it has to provide either better than similar methods errorless results or significantly shorter computation time with comparable errors. In this work the CA is compared with mathematical wave propagation solution and the Shortest Path Method (SPM). SPM uses graph theory to reconstruct seismic ray trajectory in a real, geological medium. This method was first described in Moser (1991). As it is more time-consuming than linear method, for large model the parallel approach is necessary (Pięta et al. 2013). One of the major advantages is the possibility of optimization of the modeling quality and calculation time by adjusting number of accessory nodes. This method is easily extendable to cover the anisotropy case. This work describes, verifies and validates the CA algorithms to checks the potential of use in further calculations for solving the forward problem in seismic modeling. The research shows that the presented CA method, in spite of its speed and parallelization options, can not be applied if high precision is required.

17

Porównanie efektywności podstawowych technik inwersji danych sejsmicznej tomografii refrakcyjnej w lokalizacji płytkich pustek poeksploatacyjnych

Dwornik M., Leśniak A.

WUG : bezpieczeństwo pracy i ochrona środowiska w górnictwie

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2007

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nr 6

54-55

PL

Powierzchniowa tomografia refrakcyjna jest metodą pozwalającą na odtworzenie rozkładu prędkości propagacji fal sprężystych warstw przypowierzchniowych. Niniejsza praca ma na celu porównanie następujących metod inwersji danych powierzchniowej tomografii refrakcyjnej dla prostoliniowego modelu propagacji promieni sejsmicznych w ośrodku sprężystym: dekompozycji macierzowej w oparciu o wartości własne (SVD), metod iteracyjnych ART i SIRT oraz algorytmu genetycznego. Uzyskane wyniki analizowano pod kątem stabilności rozwiązania i wierności odtworzonego obrazu z założonym modelem. Eksperymenty wykazały, że dla modelu liniowego najszybsze obliczeniowo i stosunkowo wierne rozwiązanie osiągnięto dla metody SVD. Algorytmy genetyczne, będące jedną z podstawowych technik dla modeli nieliniowych, pozwoliły na uzyskanie najlepszych wyników inwersji, kosztem znacznie dłuższych czasów obliczeniowych. Znaczne polepszenie zbieżności tej metody uzyskano dzięki zastosowaniu dodatkowego operatora w postaci iteracji SIRT dla każdego osobnika.

EN

Surface refraction tomography is a method, which is able to estimate velocity of elastic wave propagation in near-surface layers. This work shows comparison between some methods of surface refraction tomography inversion data: Singular Value Decomposition (SVD), iterative methods: ART and SIRT and genetic algorithms. In the results were analysed stability of results and error of estimated data. Numerical experiments show, that the best method are SVD. Genetic algorithms, whose are one of the basic method for non-linear models, give the best inversion results, but they takes the longest time. Significant improvement was obtained by using some iterations of SIRT in every iteration.

18

Aspekt ekonomiczny wykorzystania wód geotermalnych w ciepłownictwie. Część I

Dwornik M., Marczak A.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2002

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R. 33, nr 7-8

13-15

PL

Zastosowanie wód geotermalnych w ciepłownictwie cieszy się w Polsce coraz większyn zainteresowaniem, szczególnie ze względu na efekty ekologiczne. Jednocześnie zdecydowanie mniej miejsca poświęcono aspektom ekonomicznym stosowania tego typu technologii. W artykule dokonano próby przeglądu zagadnienń ekonomicznych, związanych z wdrożeniem energii geotermalnej w ciepłownictwie, a w szczególności w zakresie kosztów eksploatacyjnych, ceny wyprodukowania jednostki ciepła oraz nakładów inwestycyjnych. Bezpośrednim przedmiotem analizy były dane z zakładów geotermalnych w Mszczonowie (ze wspomagającą kotłownią gazową) i w Uniejowie (ze wspomagającą kotłownią olejową). Otrzymany w ciepłowniach geotermalnych efekt ekonomiczny, omówiony zostanie w odniesieniu do analogicznych danych z odpowiadających im tradycyjnych ciepłowni: gazowej oraz olejowej. We wspomnianej analizie wykorzystano obliczenia własne [4] oraz dane uzyskane z ciepłowni geotermalnych. W pierwszej części artykułu przedstawione zostaną wyniki porównania kosztów eksploatacyjnych oraz cen wyprodukowania jednostki energii cieplnej w rozpartrywanych ciepłowniach, natomiast część druga zawierać będzie analizę opłacalności, omawianych inwestycji geotermalnych.

19

Aspekt ekonomiczny wykorzystania wód geotermalnych w ciepłownictwie. Część II

Dwornik M., Marczak A.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2002

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R. 33, nr 9

3-4

PL

W pierwszej części artykułu (COW 7-8/2002) omówione zostały zagadnienia dotyczące kosztów eksploatacyjnych oraz cen wypropdukowania jednostki energii cieplnej, natomiast część druga traktować będzie o opłacalności inwestycji geotermalnych na przykładzie ciepłowni geotermalnych w Mszczonowie i Uniejowie oraz tradycyjnych - gazowych i olejowych.

20

Matematyczny opis rozkładu prędkości w osi przewodu kołowego do wykorzystania w zastosowaniach technicznych

Dwornik M.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2001

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R. 32, nr 9

20--22, 33

PL

Ze względu na pogarszający się stan czystości środowiska w Polsce, coraz większą wagę przywiązuje się do zagadnień poprawnego poboru powietrza, tak do celów wentylacyjnych, jak i procesach odpylania. W wielu przypadkach, czerpania, a szczególnie ssawa w instalacjach odpylających, ma postać prostego przewodu kołowego. Istotna staje się zatem możliwość szybkiej oceny mechanizmu poboru powietrza w celu określenia skuteczności odpylania. Staje się to możliwe przez poznanie i opisanie determinujących ich rozkładów prędkości powstających wokół ssawy.