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Tytuł:
The use of the time reverse acoustics in a shallow sea
Autorzy:
Stromkov, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/331672.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustics
shallow sea
TRM
Opis:
In this report the results of theoretical, numerical and experimental analysis of TRM in a shallow sea are submitted. It is shown that in shallow sea the characteristics of focusing depend first of all on the sizes of the array of imaginary sources which essentially exceeds the sizes of any real array. The method of an experimental research of characteristics of TRM is founded only on the receiving elements and a probe sources is offered. The spatial sizes and the form of focal area of TRM are measuired. It is experimentally confirmed the identity of focal area of TRM with one element and the vertical arrays. The estimation of efficiency of such systems is executed.
Źródło:
Hydroacoustics; 2008, 11; 353-363
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Underwater noise properties in waterway areas of the South Baltic Sea
Autorzy:
Jaśniewicz, D.
Klusek, Z.
Neves, S.
Powiązania:
https://bibliotekanauki.pl/articles/331866.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
shipping noise
shallow sea
Opis:
Results of underwater noise records completed with single and multi-hydrophone systems performed in the shallow water in the close vicinity of shipping lanes to the Gdansk/Gdynia and Świnoujście/Szczecin harbours are presented. Due to the fact that the bottom properties, bathymetry, and temporally varying sea surface alter the original sound spectra and reduce the acoustic energy, the sound transmission losses have been modelled, and an attempt to predict source levels of ships was performed. The KRAKEN sound propagation model illustrates the problems of the recognition of sources noise spectra on the basis of observations in a far zone from the sources. On the basis of the observed noise data, jointly with the AIS system the potential ecological effects of anthropogenic underwater noise on marine organisms are given for the Pomeranian Bight. In the paper, some examples of algorithms of ship noise recognition are given.
Źródło:
Hydroacoustics; 2016, 19; 173-184
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-linear water waves - experiments and theory
Autorzy:
Wilde, P.
Sobierajski, E.
Sobczak, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/241057.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
shallow water waves
laboratory experiments
Opis:
The paper concems laboratory experiments on shallow water waves. The waves in our flume were generated as programmed groups, with gentle fading-in and fading-out of amplitudes of the wavemaker's piston's motions. The higher harmonic components have been considered in the motion. Their influence on characteristics of generated waves has also been studied. The measurements were carried out at 6 cross sections along the propagation path; both wave profiles and velocities were recorded. As a description of phenomena, the wave profiles were approximated by harmonic com-ponents according to the Stokes solution. It was noted, that parameters of harmonic components change along the propagation path; there are energy transfers between them. The higher harmonic components are more significant for the description of wave profiles, than for the velocities. The results of the experiments were used in verifications in a research program on the theoretical description and numerical al-gorithm for shallow water waves generated and propagated in a flume.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2001, 48, 2; 107-128
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigating the effect of water depth on ship resistance using RANS CFD method
Autorzy:
Hoa, Nguyen Thi Ngoc
Vu, Bich Ngoc
Tran, Ngoc Tu
Chien, Nguyen Manh
Le, Tat Hien
Powiązania:
https://bibliotekanauki.pl/articles/259677.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship resistance
shallow water
RANS
Opis:
On inland waterways the ship resistance and propulsive characteristics are strictly related to the depth of the waterway, thus it is important to have an understanding of the influence of water depth on ship hydrodynamic characteristics. Therefore, accurate predictions of hydrodynamic forces in restricted waterways are required and important. The aim of this paper is investigating the capability of the commercial unsteady Reynolds– Averaged Navier–Stokes (RANS) solver to predict the influence of water depth on ship resistance. The volume of fluid method (VOF) is applied to simulate the free surface flow around the ship. The hull resistance in shallow and deep water is compared. The obtained numerical results are validated against related experimental studies available in the literature.
Źródło:
Polish Maritime Research; 2019, 3; 56-64
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Approximate solution to the Boussinesq type equations describing periodic waves
Autorzy:
Szmidt, J. K.
Powiązania:
https://bibliotekanauki.pl/articles/240984.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
Boussinesq type equations
shallow water
Opis:
The paper concerns the non-linear problem of description of shallow-water waves of finite amplitude. The description is based on the conservation-law formulation, which seems to be particularly convenient in constructing an approximate solution of the problem considered. The analysis is confined to the one-dimensional case of waves propagating in water of constant depth. In the model considered, vertical acceleration of the fluid is taken into account, and thus, the fundamental equations of the problem are similar to those given by Boussinesq (Abbott 1979). The equations differ from those frequently used in shallow-water hydrodynamics which are based on the assumption of hydrostatic pressure. An approximate solution of the problem is constructed by means of a perturbation scheme with the third order expansion of the equations with respect to a small parameter. It is demonstrated that the solution procedure may be successfully applied only within a certain range of the two ratios defining wave height to water depth and the depth to wave length, respectively.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 3; 269-285
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tracking of the broadband source of the underwater noise in the very shallow water conditions
Autorzy:
Grelowska, G.
Kozaczka, E.
Powiązania:
https://bibliotekanauki.pl/articles/331537.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
broadband signals
shallow water
sound propagation
Opis:
The paper contains the results, both theoretical and experimental, connected with the tracking of the underwater noise source as small ships, pontoon, diver and so on. The problem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is taken into account the detection of the sources that move on the surface of the sea or underwater in shallow and very shallow water. The main goal deals with characterization of the sound propagation at the shallow water channel. The next problem is formulation of the sound propagation inside of this acoustic duct including normal mode creations and dispersion of the acoustic energy. When we take into account the small ships noise the two main sources are analyzed. The first one is the vibration energy produced by the mechanisms located inside of the ship hull. The acoustical energy is transformed through structural elements of the hull to surrounding water. This energy propagates as broadband underwater noise. The next source is the ship propeller. The sources of the underwater noise give the some deposit to the total acoustical energy that means the ambient noise. The problem that should be solved is to discover these acoustical disturbances along with their classification, identification and tracking.
Źródło:
Hydroacoustics; 2015, 18; 77-86
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental studies of low-frequency acoustic fields in a shallow sea
Autorzy:
Luchinin, A. G.
Powiązania:
https://bibliotekanauki.pl/articles/332794.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
experimental studies
acoustic fields
shallow sea
Opis:
The results of the studies of excitation and propagation of low-frequency acoustic fields in a shallow sea, which have been carried out at the IAP RAS for several years, are discussed. A novel equipment complex designed specially for these experiments and intended for the selective excitation and reception of waveguide modes is described. Examples of measurements of various characteristics of low-order mode acoustic signals are given, which demonstrate high efficiency of the applied equipment and measurement technique.
Źródło:
Hydroacoustics; 2009, 12; 117-126
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metodika ocenki dvizenia sudov na melkovodnyh ucastkah
Techniques for the assessment of ships in shallow areas
Autorzy:
Arefyev, I.
Powiązania:
https://bibliotekanauki.pl/articles/359847.pdf
Data publikacji:
2012
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
transport
shallow water
ship
environment
evaluation
Opis:
A method for assessing the impact of low water in the fairway on the movement of ships in the rivers and canals is shown in the work. The growth speed of the ship breaks down the river (channel), the territory of the area. It is important that when the motion is regular. This paper is an analysis of this problem.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2012, 31 (103); 19-23
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of hybrid MT for related languages
Autorzy:
Homola, P.
Kubon, V.
Powiązania:
https://bibliotekanauki.pl/articles/969803.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
machine translation
related languages
shallow methods
Opis:
The paper introduces a hybrid approach to a very specific field in machine translation - the translation of closely related languages. It mentions previous experiments performed for closely related Scandinavian, Slavic, Turkic and Romanic languages and describes a novel method, a combination of a simple shallow parser of the source language (Czech) combined with a stochastic ranker of (parts of) sentences in the target language (Slovak, Russian, Slovenian). The ranker exploits a simple stochastic model of the target language and its main task is to choose the best translation among those provided by the system. The last section of the paper presents results indicating better translation quality compared to the existing MT system for Czech and Slovak and compares them with the results obtained by the translation from Czech to Russian using the same system.
Źródło:
Control and Cybernetics; 2010, 39, 2; 421-438
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
White noise excited vibrations of viscoelastic shallow shells
Autorzy:
Nizioł, J.
Kozień, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/279764.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
shallow shells
vibrations
viscoelasticity
white noise
Opis:
The paper presents the results of the analysis of randomly excited vibrations of viscoelestic shallow shells. The parameter of interest is the dispersion of velocity normal to the element surface. The choice of parameter is motivated by estimation of the noise generated by a vibrating panel.
Drgania lepkosprężystych powłok małowyniosłych poddanych wymuszeniu losowemu typu białego szumu W artykule omówiono rezultaty analiz drgań powłok małowyniosłych wykonanych z materiału lepkosprężystego i poddanych wymuszeniu losowemu typu białego szumu. Jako parametr opisujący drgania przyjęto dyspersję składowej prędkości normalnej do powierzchni środkowej powłoki. Wybór tego parametru jest uzasadniony faktem, iż jego wartość może być miarą wartości mocy akustycznej promieniowanej przez drgający element.
Źródło:
Journal of Theoretical and Applied Mechanics; 2000, 38, 2; 351-366
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the vertical distribution of the sound speed of the Gulf of Gdansk in the years 2000-2010
Autorzy:
Grelowska, G.
Witos, D.
Powiązania:
https://bibliotekanauki.pl/articles/332481.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
shallow water acoustics
underwater acoustic climate
Opis:
The conditions of the acoustic wave propagation in the southern Baltic are much more complex than in other shallow waters. In the typical shallow water, seasonal changes in acoustical conditions in the upper layer, of the depth of about 60-70 m, are observed. They are caused by variation of the annual meteorological conditions. Most often, in the deep water layer, acoustical conditions are stable throughout the year. However, in the Southern Baltic they change during the year also in the deep water layer. They depend on the inflows of highly saline water from the Northern Sea through the Danish Straits, which evoke a dense bottom current increasing the salinity at the bottom. The vertical sound speed distribution in the Southern Baltic is strongly dependent on the hydrological conditions. In the paper the characteristic elements of acoustic climate of the Southern Baltic will be considered, based on data concerning the Gulf of Gdansk. Averaged characteristics of temperature, salinity and sound speed for the years 2000-2010, as well as anomalies, have been determined.
Źródło:
Hydroacoustics; 2016, 19; 129-137
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-dimensional shallow water model for rapidly and gradually varied flow
Autorzy:
Szydłowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/241012.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
Two-dimensional shallow water model
rapidly varied flow
gradually varied flow
shallow water equations
eddy viscosity terms
Opis:
The numerical solution of full shallow water equation (SWE) including the eddy viscosity terms is presented. In the first part of the paper the solution of the homogeneous part of SWE for discontinuous, rapidly varied flow is reported. The method presented here is based on Roe idea of numerical fluxes of mass and momentum. The numerical solution of SWE on unstructured, triangular mesh is reported and the influence of geometry approximation is examined. The imposing of the boundary condition on a triangular numerical mesh is described in detail. The consistent with finite volume method (FVM) approximation of the viscous part of SWE is presented. The procedure similar to the finite element method (FEM) is used to calculate the function derivatives inside the finite volumes. The specific difficulties of source terms numerical integration are studied and some methods to avoid these problems are presented. To integrate the bottom friction term the splitting technique is implemented. The computed results are compared to analytical solution of Saint-Venant equations, experimental data and results available in the literature. Good agreement between these results is observed.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2001, 48, 1; 35-61
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Groundwater Vulnerability Using the DRASTIC Method in Ouargla Shallow Aquifer (Algerian Sahara)
Autorzy:
Satouh, Adel
Boualem, Bouselsal
Chellat, Smaine
Benaabidate, Lahcen
Powiązania:
https://bibliotekanauki.pl/articles/1838286.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Ouargla
shallow aquifer
vulnerability
DRASTIC
land-use
Opis:
Groundwater is the main source for many uses around the city of Ouargla. In this study, the DRASTIC method was used to assess the vulnerability of the groundwater aquifer. Seven hydrogeological parameters of the model (D water depth, R efficient charging, A aquifer type, S soil type, T topography, I unsaturated zone and C hydraulic conductivity) were measured and mapped. The intrinsic vulnerability map of the shallow aquifer, using the DRASTIC method, shows a high to very high vulnerability to pollution; 91.6% of the study area has high vulnerability, 8.4% of it has very high vulnerability. The comparison of the DRASTIC maps with the land use map illustrates that the agglomerations and irrigated areas are the most vulnerable areas to pollution, due to the low depth of the aquifer and the infiltration of significant domestic and irrigation wastewater. The results show that the relationship coefficient between the DRASTIC index and nitrate concentration is R = 0.73. This indicates that the groundwater vulnerability mapping by using the DRASTIC method can be applied for sensible groundwater resources management and land-use planning in the study area.
Źródło:
Journal of Ecological Engineering; 2021, 22, 6; 12-19
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Groundwater Vulnerability Using the DRASTIC Method in Ouargla Shallow Aquifer (Algerian Sahara)
Autorzy:
Satouh, Adel
Boualem, Bouselsal
Chellat, Smaine
Benaabidate, Lahcen
Powiązania:
https://bibliotekanauki.pl/articles/1838393.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Ouargla
shallow aquifer
vulnerability
DRASTIC
land-use
Opis:
Groundwater is the main source for many uses around the city of Ouargla. In this study, the DRASTIC method was used to assess the vulnerability of the groundwater aquifer. Seven hydrogeological parameters of the model (D water depth, R efficient charging, A aquifer type, S soil type, T topography, I unsaturated zone and C hydraulic conductivity) were measured and mapped. The intrinsic vulnerability map of the shallow aquifer, using the DRASTIC method, shows a high to very high vulnerability to pollution; 91.6% of the study area has high vulnerability, 8.4% of it has very high vulnerability. The comparison of the DRASTIC maps with the land use map illustrates that the agglomerations and irrigated areas are the most vulnerable areas to pollution, due to the low depth of the aquifer and the infiltration of significant domestic and irrigation wastewater. The results show that the relationship coefficient between the DRASTIC index and nitrate concentration is R = 0.73. This indicates that the groundwater vulnerability mapping by using the DRASTIC method can be applied for sensible groundwater resources management and land-use planning in the study area.
Źródło:
Journal of Ecological Engineering; 2021, 22, 6; 12-19
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The extent of the unconfined aquifer based on the Dempster-Shafer theory on the example of postglacial sandur area
Autorzy:
Kachnic, M.
Powiązania:
https://bibliotekanauki.pl/articles/2063008.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
unconfined aquifer
shallow aquifer
Dempster-Shafer theory
probabilistic
Opis:
The research aimed to present an application of the technique based on the Dempster-Shafer theory for the determination of the shallow unconfined aquifer extent in a nonparametric (probabilistic) scale. The geology of research area is predominantly composed of the Pleistocene postglacial sediments. Only unconfined aquifers were taken into account in the study described in these paper. The resulting image showed a map of the aquifers’ extents in a probabilistic scale i.e. in a range between 0 (the lack of the aquifer, which is confirmed by research) and 1 (confirms the occurrence of the aquifer proved by research). Data analyses were carried out in the Geographic Information System. All the data were imported to the IDRISI. The Dempster-Shafer probability theory supported by the module BELIEF of IDRISI software was applied to the algebra of pixel maps.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2010, 441 Hydrogeologia z. 10; 55--61
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultra-shallow nitrogen plasma implantation for ultra-thin silicon oxynitride (SiOxNy) layer formation
Autorzy:
Bieniek, T.
Beck, R. B.
Jakubowski, A.
Kudła, A.
Powiązania:
https://bibliotekanauki.pl/articles/308830.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
MOS technology
plasma processing
shallow implantation
radiation damage
Opis:
The radiation damage caused by low energy r.f. plasmas has not been, to our knowledge, studied so far in the case of symmetric planar plasma reactors that are usually used for PECVD processes. The reason is that, unlike nonsymmetrical RIE reactors, such geometry prevents, basically, high-energy ion bombardment of the substrate. In this work, we present the results of experiments in which we have studied the influence of plasma processing on the state of silicon surface. Very low temperature plasma oxidation has been used as a test of silicon surface condition. The obtained layers were then carefully measured by spectroscopic ellipsometry, allowing not only the thickness to be determined accurately, but also the layer composition to be evaluated. Different plasma types, namely N2, NH3 and Ar, were used in the first stage of the experiment, allowing oxidation behaviour caused by the exposure to those plasma types to be compared in terms of relative differences. It has been clearly proved that even though the PECVD system is believed to be relatively safe in terms of radiation damage, in the case of very thin layer processing (e.g., ultra-thin oxynitride layers) the effects of radiation damage may considerably affect the kinetics of the process and the properties of the formed layers.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 1; 70-75
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Description of Long Water Waves in Material Variables
Autorzy:
Szmidt, K.
Hedzielski, B.
Powiązania:
https://bibliotekanauki.pl/articles/241085.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
long waves
shallow water
unsteady motion
sloping beach
Opis:
Shallow water equations formulated in material variables are presented in this paper. In the model considered, a three-dimensional physical problem is substituted by a two-dimensional one describing a transformation of long waves in water of variable depth. The latter is obtained by means of the assumption that a vertical column of water particles remains vertical during the entire motion of the fluid. Under the assumption of small, continuous variation of the water depth, the equations for gravity waves are derived through Hamilton's principle formulated in terms of the material coordinates. This formulation ensures the conservation of mechanical energy. The approximation depends on the wave parameters as well as on the bed bathymetry. The latter may influence a solution of the model decisively; thus, one should be careful in applying the description to complicated geometries of fluid domains encountered in engineering practice.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2009, 56, 1-2; 63-83
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship seakeeping in UKC determination – a further study on wave force transfer functions
Autorzy:
Artyszuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/359064.pdf
Data publikacji:
2012
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
ship seakeeping
ocean wave
shallow water
motion dynamics
Opis:
Modeling of ship motions in waves concentrates in most applications on the response amplitude operator (RAO). This mathematically not demanding method of analysis is very attractive, but loses some essential information in certain situations. The objective of present contribution is to establish and investigate preliminary foundations for a seakeeping model as optimal for under keel clearance (UKC) estimation. A special attention was devoted to transients of motions, stationary harmonic motions, coupling between degrees of freedom, and the wave force transfer functions – all in the aspect of shallow water environment.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2012, 32 (104) z. 2; 5-15
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free sailing model tests of evasive action manoeuvre of a river cargo motor barge in shallow waters
Autorzy:
Górski, W.
Reichel, M.
Powiązania:
https://bibliotekanauki.pl/articles/259673.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow water
free sailing
inland water motor barge
Opis:
The paper presents shallow water experiments of a self-propelled, free running model of an inland water motor barge. In accordance with the Rhine Manoeuvring Standards Rheinschiffsuntersuchungsordnung (RheinSchUO 1995, issue 2005), evasive action manoeuvring tests were realised. Model obtained from DST Duisburg Germany was a 5.00 meters long motor barge built to a scale of 1:20 and propelled with an 80 mm diameter ducted propeller. Tests were carried out in the auxiliary towing tank of the Ship Hydromechanics Division in Gdańsk. The experiment consisted of efficiency analysis of different rudder blades with variable rudder profiles and rudder blade areas. In total the evasive action test was repeated for three different rudder profiles, with three different chord lengths and at three different water depths each. For each particular case the total standard manoeuvre time and side rudder force was measured. These results were compared with the RheinSchUO standards. The model tests programme was realised within the EU CREATING project supported in the 6th Framework Programme.
Źródło:
Polish Maritime Research; 2007, S 2; 95-97
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Transformation of Long Gravitational Waves in a Region of Variable Water Depth: a Comparison of Theory and Experiment
Autorzy:
Szmidt, K.
Powiązania:
https://bibliotekanauki.pl/articles/241424.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
shallow water
nonlinear waves
non-uniform water depth
Opis:
The paper describes investigations on transformation of long gravitational waves in water of variable depth with reflection of the waves from a shelf barrier. In the model considered, a long water wave arrives from an area of constant water depth to an area of constant, smaller water depth, where it reflects at a vertical wall. The analysis is confined to a finite fluid domain, relevant to experimental investigations in a laboratory flume. In theoretical analysis of the phenomenon, we follow a non-linear shallow water approximation to the problem considered. The fundamental equations of fluid motion are derived with the help of a standard variational procedure in a material system of coordinates. The equations proved to be a reasonable approximation to a description of the long waves propagating in fluid with small variation of its depth. In the discussed case of reflection of such waves from a vertical barrier, however, the motion of the fluid is more complicated and therefore the long water wave theory does not deliver as good results as in the case of pure propagation of the waves. The primary objective of this paper is thus to compare the theoretical solution proposed with data obtained in experiments, and to answer the question about accuracy and applicability of the theoretical model in the description of the problem investigated.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2007, 54, 2; 137-158
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola płytkiego nizinnego zbiornika zaporowego w układzie "rzeka-zbiornik-rzeka" Część II. Przemiany i bilans związków fosforu w zbiorniku Słupsko
The role of shallow, lowland dam reservoir in the river-lake-river system. Part II. The phosphorus changes and budget in the Slupsko Dam-Reservoir
Autorzy:
Kostecki, M.
Nocoń, W.
Powiązania:
https://bibliotekanauki.pl/articles/296754.pdf
Data publikacji:
2010
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
płytki zbiornik zaporowy
fosfor
shallow dam reservoir
phosphorus
Opis:
Przedstawiono wpływ płytkiego nizinnego zbiornika zaporowego Słupsko (Górny Śląsk) na zmiany stężeń i ładunków związków fosforu w Potoku Toszeckim. Zbiornik Słupsko funkcjonuje w warunkach wysokiego obciążenia zewnętrznego fosforem, co stwarza warunki dla degradacji tego ekosystemu. Bilans fosforu wykazał, że zbiornik nie zmniejsza dopływającego ładunku fosforu, zatem z punktu widzenia ochrony zbiornika Pławniowice jego rola jest niewielka. Zbiornik Słupsko na obecnym etapie swojego funkcjonowania i w aktualnych uwarunkowaniach zmienia mineralne formy fosforu na organiczne. Odwrotna zależność wielkości ładunków fosforu od wielkości przepływu na dopływie do zbiornika oraz widoczny efekt rozcieńczania wskazują na równomierne w czasie wprowadzanie do wód związków fosforu na terenie zlewni. Ustalenie źródeł pochodzenia fosforu na terenie zlewni zbiornika oraz ich eliminacja wydatnie poprawi jakość wody zarówno w Potoku Toszeckim, jak i w zbiornikach Słupsko i Pławniowice.
The influence of a shallow, lowland dam-reservoir (the Słupsko reservoir in Upper Silesia) on the changes of concentration and loads of phosphorus in the Potok Toszecki is presented. The Słupsko reservoir functions in the high phosphorus external load conditions, what causes its degradation. The phosphorus budget showed that only small amount of the phosphorus load inflowed to the reservoir is reduced. In this case the role of reservoir for protection of the Pławniowice reservoir is not important. At the present phase of the reservoir functioning and in the current environmental conditions, in the Słupsko dam-reservoir mineral forms of phosphorus change to the organic forms. The inverse function relationship between phosphorus loads and velocity of flow as well as the dilution effect show that the regular load of phosphorus is introduced from the catchment area. Location of phosphorus sources in the Słupsko dam-reservoir basin and their elimination could improve the water quality in the Potok Toszecki as well as in the Słupsko and the Pławniowice dam-reservoirs.
Źródło:
Inżynieria i Ochrona Środowiska; 2010, 13, 4; 245-257
1505-3695
2391-7253
Pojawia się w:
Inżynieria i Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of ship-generated noise in shallow sea
Autorzy:
Kozaczka, E.
Grelowska, G.
Powiązania:
https://bibliotekanauki.pl/articles/259166.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow water acoustics
propagation of acoustic waves in water layer
wave modes in shallow sea
underwater noise produced by ship
Opis:
Contamination of sea environment by noise and any energy radiated to water constitutes today a problem to which more and more attention is paid, in view, a.o., of consequences of an impact of these factors onto marine fauna. European Union has introduced a directive by which EU countries are made responsible to undertake efforts aimed at reaching a good envirenmental status of European seas by 2020. A main source of underwater noise is sea transport of any kind. Propagation of underwater acoustic disturbances in the Baltic Sea highly differs from the course of the phenomenon in a deep sea. Model of spherical propagation cannot be applied to this case in view of water environment limitation by seabed and free water surface, i.e. a reduction of the problem to wave propagation in a water layer of the depth comparable with acoustic wave length. This paper is aimed at demonstration of possible assessment of range of acoustic disturbances generated by a ship sailing in shallow sea, by using a method described in the work [13]. The research was made on the basis of results of own measurements of underwater noise produced by ships in the Gdansk Bay area. An important factor which decIdes on a range of underwater disturbances is a kind of seabed sediments. In this paper there are presented results of numerical investigations based on real data dealing with noise produced by a selected floating unit (ship) for selected characteristic spectral components. The simulations were conducted for the shallow sea model of definite physical parameters such as acoustic wave propagation velocity, geometrical dimensions (water depth) and seabed acoustic parameters as well.
Źródło:
Polish Maritime Research; 2018, 2; 37-46
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Disappeared almost without a trace : Taphonomic pathways and the recognition of hidden bioturbation events in Eocene storm deposits (Paují Formation, Lake Maracaibo, Venezuela)
Autorzy:
Buatois, L. A.
Delgado, M.
Mángano, M. G.
Powiązania:
https://bibliotekanauki.pl/articles/191974.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
trace fossils
ichnofabric
taphonomic pathways
tempestites
shallow marine
Eocene
Opis:
Shallow-marine deposits, included in the “Basal Sands” of the Eocene Paují Formation of the Maracaibo Basin in western Venezuela, record deposition in fore shore to lower off shore settings. These deposits are stacked in coarsening-upward parasequences that reflect variable intensities and frequencies of storms. Of particular interest are sharp-based, amalgamated, hummocky cross-stratified and rippled, very fine-grained sandstone beds, observed in the core MOT-X from the Motatán Field. These beds record storm deposition, under purely oscillatory to combined flows in an offshore-transition setting. The amalgamated nature of the sand stone interval indicates repeated erosion, due to multiple storm events. The ichnofabrics in these tempestites result from a distinctive taphonomic pathway, reflecting the interplay between bioturbation events and storm erosion and deposition. The storm-related trace-fossil suite is represented by Diplocraterion parallelum and local occurrences of Palaeophycus tubularis, Bergaueria isp. and Thalassinoides isp., which is consistent with the relatively high energy of formation of these deposits. Fair-weather deposits are absent from the sand stone interval. However, high densities of Chondrites isp. are present in the infills of Diplocraterion parallelum and, more rarely, Thalassinoides isp. providing the sole evidence of the establishment of a resident fauna during inter-storm intervals. Deposits containing the fair-weather suites were erosionally removed during the subsequent storm. The deep-tier emplacement of Chondrites and the ability of its producer to rework other biogenic structures favour preservation, allowing recognition of a “hidden” bioturbation event that otherwise might have remained undetected.
Źródło:
Annales Societatis Geologorum Poloniae; 2015, 85, 3; 473-479
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A nonlinear model of a turbine blade by asymptotic analysis
Autorzy:
Rodriguez, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/907896.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
matematyka
asymptotic analysis
nonlinear elasticity
junctions
shallow shells
multistructures
Opis:
In this paper we obtain a limit model for a turbine blade fixed to a 3D solid. This model is a three-dimensional linear elasticity problem in the 3D part of the piece (the rotor) and a two-dimensional problem (the nonlinear shallow shell equations) in the 2D part (the turbine blade), with junction conditions in the part of the turbine blade fixed to the rotor. To obtain this model, we perform an asymptotic analysis, starting with the nonlinear three-dimensional elasticity equations on all the pieces and taking as a small parameter the thickness of the blade.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2002, 12, 1; 101-113
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of shallow groundwater suitability for irrigation purposes : A case study from Doornfontein area, South Africa
Autorzy:
Moges, Simeneh S.
Dinka, Megersa O.
Powiązania:
https://bibliotekanauki.pl/articles/28411663.pdf
Data publikacji:
2023
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
irrigation
Johannesburg
physico-chemical parameters
shallow groundwater
water quality
Opis:
The present study aims at evaluating the quality of shallow groundwater (SGW) and its suitability for irrigation purpose in the most urbanised part of Johannesburg city, South Africa. The SGW samples were collected in three consecutive years and analysed for 20 selected physicochemical parameters, and heavy metals. The results were compared with the South African water quality, and Food and Agricultural Organization irrigation water quality guidelines, and standard indices derived from laboratory outputs. The results of the study show that all physiochemical parameters and heavy metals were within the limits set by both guidelines for irrigation purposes, except for potassium (3.58 mg∙dm-3) and manganese levels (3.152 mg∙dm-3). The calculated irrigation parameter values of sodium adsorption ratio (SAR), sodium percentage (Na%), residual sodium carbonate (RSC), magnesium hazard (MH), Kelly’s ratio (KR) and permeability index (PI) were within the permissible range of irrigation water quality standards. The findings of this study provide helpful information for decision-makers such as utilisation of the studied groundwater for irrigation uses.
Źródło:
Journal of Water and Land Development; 2023, 58; 189--197
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D Modeling of Wave Propagation in Shallow Water by the Method of Characteristics
Autorzy:
Khalilabadi, Mohammad Reza
Powiązania:
https://bibliotekanauki.pl/articles/31340098.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
wave propagation
shallow water
MOC method
waveguide
transmission loss
Opis:
In this paper, a 2D numerical modeling of sound wave propagation in a shallow water medium that acts as a waveguide, are presented. This modeling is based on the method of characteristic which is not constrained by the Courant–Friedrichs–Lewy (CFL) condition. Using this method, the Euler time-dependent equations have been solved under adiabatic conditions inside of a shallow water waveguide which is consists of one homogeneous environment of water over a rigid bed. In this work, the stability and precision of the method of characteristics (MOC) technique for sound wave propagation in a waveguide were illustrated when it was applied with the semi-Lagrange method. The results show a significant advantage of the method of characteristics over the finite difference time domain (FDTD) method.
Źródło:
Archives of Acoustics; 2022, 47, 3; 407-412
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contribution of Soft-shelled Monothalamous Taxa to Foraminiferal Assemblages in the Adriatic Sea
Autorzy:
Sabbatini, Anna
Nardelli, Maria Pia
Morigi, Caterina
Negri, Alessandra
Powiązania:
https://bibliotekanauki.pl/articles/763441.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Soft-shelled foraminifera, Allogromiids, shallow water setting, Adriatic Sea, bioindicator
Opis:
Monothalamous foraminifera with organic and agglutinated test walls (‘‘allogromiids’’ sensu lato) deserve attention because of their importance in deep-sea and shallow-water soft-bottom communities and their crucial phylogenetic position at the base of the foraminiferal evolutionary tree. However, our knowledge of the biodiversity and ecology of monothalamous foraminifera is very incomplete and geographically patchy. Here, we present a short review based on the available data on monothalamous, soft-walled foraminiferal taxa from the Adriatic Sea in response to several environmental parameters (i.e., organic matter, oxygen, grain size, depth). The main results of the studies provide evidence of the importance of these foraminiferal taxa in this shallow, temperate latitude area;they represent a start for the identification of soft-shelled monothalamous morphotypes that could be potential bioindicators of environments influenced by inputs of fresh waters, increasing eutrophication and consequent fluctuations in bottom-water oxygenation. The contribution of this soft-shelled component to living benthic foraminiferal assemblages appears not negligible and excluding it from foraminiferal studies can potentially lead to a loss of ecological information. The study, therefore, provide an atlas of the Adriatic soft-shelled foraminiferal taxa in order to 1) encourage the species-level description, if possible, or alternatively a basic morphotype characterization, 2) facilitate future comparisons of taxa from similar settings, 3) promote their potential use in future biomonitoring investigations together with the hard-shelled foraminifera.
Źródło:
Acta Protozoologica; 2013, 52, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ichnology of the Cambrian Ociesęki Sandstone Formation (Holy Cross Mountains, Poland)
Autorzy:
Stachacz, M.
Powiązania:
https://bibliotekanauki.pl/articles/191282.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Cambrian
trace fossils
shallow-water marine deposition
Holy Cross Mountains
Opis:
Quartz arenites and wackes with intercalations of silty shales of the Ociesęki Formation were analysed in small outcrops and one core. The succession contains about forty-three ichnogenera and seventy-four ichnospe- cies, among which thirty-three ichnogenera and fifty-three ichnospecies are described by present author. The formation belongs to the Schmidtiellus-Holmia Superzone and to the Protolenus-Issafeniella Zone. Most strata are totally bioturbated. The diverse and numerous trace fossils represent the Cruziana ichnofacies in the lower part of the formation and the Skolithos ichnofacies in the upper part. A few possibly new ichnospecies of different ichnogenera have been described in open nomenclature. Sedimentary structures and trace fossil assemblages indicate that the older part of this formation was deposited on the upper offshore to lower shoreface, while its younger part was deposited on the lower to middle shoreface, where storm episodes were the main factor controlling sedimentation and the activity of benthos. The trace fossil associations studied are similar to those from the lower Cambrian in many places around the world. The ichnoassociations from the Polish part of the East European Platform and from Sweden, which represent the Baltica palaeocontinent, display the closest similarity.
Źródło:
Annales Societatis Geologorum Poloniae; 2016, 86, 3; 291-328
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the quality of shallow groundwaters on the occurrence of selected relic plant species of peatlands in the Łęczna-Włodawa Lakeland
Autorzy:
Serafin, Artur
Pogorzelec, Magdalena
Bronowicka-Mielniczuk, Urszula
Powiązania:
https://bibliotekanauki.pl/articles/292495.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
groundwater quality
peatlands
physical-chemical parameters
relic species
shallow groundwaters
Opis:
The aim of the study was to compare the physical-chemical quality parameters of shallow groundwater quality in peat bogs of the Łęczna-Włodawa Lake District in the context of the occurrence of selected boreal species of plant relics: dwarf birch (Betula humilis Schrank), downy willow (Salix lapponum L.) and swamp willow (Salix myrtylloides L.). Analyzes of shallow groundwater quality parameters included physical-chemical parameters: reaction (pH), electrolytic conductivity (EC), dissolved organic carbon (DOC), total nitrogen (TN), ammonium nitrogen (NH4), nitrite nitrogen (NO2), nitrate nitrogen (NO3), total phosphorus (TP), phosphate (PO4), sulfate (SO2), sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg) by certified laboratory tests. It was found that the natural hydrochemical specification of peat bogs is characterized by fluctuations associated with the dynamics of internal metabolism of peat ecosystems without the visible impact of anthropopressure. This is confirmed by the concentration of nutrients: TN at the study sites were within a broad range of mean values: 16.92–45.31 mg·dm–3; NH4 (0.55–0.76 mg·dm–3); NO2 (0.06–4.33 mg·dm–3); and NO3 did not exceed 0.2 mg·dm–3, and concentration of TP adopted mean values in a range of 0.22–0.42 mg·dm–3. The studied physical-chemical factors of shallow groundwater were within the habitat preferences of the studied species, but in differentiated qualitative and quantitative ways determined optimal conditions for building the population of the studied species. Particularly values of TP lower than other obtained values in a range of: 0.08–0.32 mg·dm–3; PO4 = 0.1 mg·dm–3; TN = 2.2–21.2 mg·dm–3; NH4 = 0.1–0.46 mg·dm–3; DOC = 24.6–55.9 mg·dm–3, as well as higher than average pH values in a range of: 5.34–5.95 and concentration of Ca = 5.67–28.1 mg·dm–3 and Mg = 0.56–2.41 mg·dm–3, as well as EC = 72.1–142.3 μS·cm–1 can be treated as a condition favouring proper development of the population of dwarf birch. For Salix lapponum: a reduced level of values of nitrogen fractions (TN = 3.01–18.84 mg·dm–3; NH4 = 0.1–0.41 mg·dm–3), a reduced level of values of phosphorus fractions (TP = 0.09–0.44 mg·dm–3; PO4 = 0.1–0.44 mg·dm–3), part of ions (Ca = 4.39–19.63 mg·dm–3; Mg = 0.77–3.37 mg·dm–3), pH = 5.9–6.4, EC = 124–266 μS·cm–1 and DOC = 24.1–57.5 mg·dm–3. For the equally studied Salix myrtylloides, such conditions were met by: TP = 0.1–0.41 mg·dm–3; PO4 = 0.1–0.18 mg·dm–3, DOC = 27.5–50.9 mg·dm–3, pH = 5.3–5.94 and EC = 62.2–139.3 μS·cm–1.
Źródło:
Journal of Water and Land Development; 2020, 45; 133-142
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated sedimentological and ichnological study of the Coniacian sedimentation in North Sudetic Basin, SW Poland
Autorzy:
Leszczyński, S.
Powiązania:
https://bibliotekanauki.pl/articles/2060087.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
lithofacies
ichnofacies
trace fossils
shallow marine
paralic
North Sudetic Synclinorium
Opis:
Lithofacies and ichnological features of the Coniacian deposits of the upper part of Żerkowice Member and lowest part of the overlying Czerna Formation in southeastern part of the North Sudetic Synclinorium are described and their sedimentary palaeoenvironment is interpreted. The study confirms a shallow-marine to paralic/paludine palaeoenvironment. Sedimentation of the Żerkowice Member occurred in an upper shoreface environment dominated by waves, tidal currents and wave-generated alongshore currents, with an episodic encroachment of fore shore zone and shoal-water deltas. The interpretation is supported by a high-diversity assemblage of trace fossils with 21 ichnogenera, representing a stressed expression of the Skolithos Ichnofacies dominated by Ophiomorpha nodosa and a proximal expression of the Cruziana Ichnofacies with Thalassinoides and rare specimens of diverse other ichnotaxa. Sedimentation of the Czerna Formation commenced after a stasis, with at least a local hiatus caused by emergence, and proceeded in a laterally and vertically more varied environment, with transgressive coastal lagoons evolving into freshwater lakes and marshes and with a repetitive regressive intrusion of shoreface and shoal-water deltas. The emergence of the area is recorded by coal-bearing deposits with plant-root traces. Local occurrence of the Teredolites Ichnofacies in coal (peat) deposits above the base of the Czerna Formation indicates renewed marine flooding. Continuation of the latter is locally evidenced by a trace-fossil assemblage with 17 ichnogenera, representing proximal expression of the Cruziana Ichnofacies followed by distal expression of the Skolithos Ichnofacies in the overlying transgressive-regressive cyclothems. The palaeoenvironmental changes recorded by the sedimentary succession indicate bathymetric fluctuations and imply considerable shoreline shifts and palaeogeographic changes in the basin. These changes are interpreted as a combined signal of 2nd- and 3rd-order eustatic cycles, modified and partly obliterated by the effects of intrabasinal tectonic forcing and by palaeogeographically controlled variation in sediment supply.
Źródło:
Geological Quarterly; 2018, 62, 4; 767--816
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mention Detection for Coreference Resolution in Polish. Development of the Formal Grammar
Autorzy:
Wójcicka, Alicja
Kopeć, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/677372.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Slawistyki PAN
Tematy:
coreference resolution
mention detection
shallow parsing
Formal Grammar for Polish
Opis:
Mention Detection for Coreference Resolution in Polish. Development of the Formal GrammarThis paper presents the results of an improvement and extension of the Shallow Grammar of Polish, designed for the needs of the Computer-based Methods for Coreference Resolution in Polish Texts (CORE) project. The role of the Grammar was to detect nominal groups (i.e. multi-level nested phrases) that could be considered as mentions in coreference resolution tasks. In this article, the reorganization and changes to the Grammar are described, as well as the results of an evaluation of the Polish Coreference Corpus with manual annotations of mentions and coreferential expressions. A comparison of the second version of the Grammar with an evaluation of the first version reveals an improvement to the recall and F1 measures. Parsing płytki relacji koreferencji w języku polskim. Rozwój gramatyki formalnejCelem artykułu jest przedstawienie rezultatów prac zmierzających do rozszerzenia gramatyki powierzchniowej języka polskiego, stworzonej na potrzeby projektu "Komputerowe metody identyfikacji nawiązań w tekstach polskich" (grant NCN nr 6505/B/T02/2011/40), oraz poprawy wyników jej działania. Rolą gramatyki powierzchniowej jest wykrywanie grup nominalnych, które mogą wchodzić w relację koreferencji z innymi wyrażeniami w tekście. Nowa gramatyka została przetestowana z użyciem Polskiego Korpusu Koreferencyjnego, w którym grupy nominalne oraz relacje koreferencji między nimi zostały oznaczone ręcznie. Porównanie nowej wersji gramatyki z wersją poprzednią wykazało poprawę zarówno skuteczności wykrywania odpowiednich grup, jak i wzrost miary F1.
Źródło:
Cognitive Studies; 2016, 16
2392-2397
Pojawia się w:
Cognitive Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Precipitation amounts triggering landslide processes in the western part of the Nałęczów Plateau (Lublin Upland, Poland)
Autorzy:
Demczuk, Piotr
Zydroń, Tymoteusz
Szafran, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/15805023.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
slope stability
shallow landslide
rainfall thresholds
loess
the Nałęczów Plateau
Opis:
This study covers the western part of Poland’s loess Nałęczów Plateau (Kazimierz Dolny, Zbędowice). Mass movements in the Lublin Upland occur during periods of increased precipitation or after a snowy and cold winter. To date, there are no comprehensive studies on active (precipitation, hydrology, vegetation, land use, anthropogenic factors) or passive factors (lithology, slope angle) causing such geohazards in this region. This area’s formations are characterised by high sensitivity to even small changes in moisture content; thus, their geotechnical parameters deteriorate as a result of precipitation or rising groundwater levels. The calculations in this study were chosen to determine the time necessary for ground response to external factors, in addition to determining the impact of these factors on decreases in the factor of safety (FS). Based on calculations in GeoStudio software, the impacts of rainfall totals and duration on slope failure, interpreted as an event where the FS falls below 1.0, were analysed. Accordingly, the threshold rainfall value was determined as the total rainfall at the time of slope failure. The study’s results indicate that loess covers are characterised by average water permeability, relatively high internal friction angles and low cohesion, which, combined with high slope inclination, favour landslide formation even when the slope is only partially saturated. The most unfavourable stability conditions occur at the beginning of spring, indicating that loess stability is significantly affected by snowmelt and precipitation at the beginning of the vegetation season, as well as the occurrence of episodic intense precipitation during the summer.
Źródło:
Quaestiones Geographicae; 2022, 41, 3; 33-51
0137-477X
2081-6383
Pojawia się w:
Quaestiones Geographicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Agresywność chemiczna płytkich wód podziemnych Wrocławia
Chemical aggressiveness of shallow groundwater in Wrocław
Autorzy:
Trałka, Marta
Modelska, Magdalena
Błachowicz, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2076166.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
agresywność chemiczna
płytkie wody gruntowe
Wrocław
chemical aggressiveness
shallow groundwater
Opis:
Evaluation of the chemical aggressiveness of shallow ground - water for the area of Wrocław was performed in accordance with the Polish Standard (PN-EN 206+A1:2016-12). This standard requires determination of pH and concentration of ammonium, magnesium, sulphate and aggressive carbon dioxide in water. The research was carried out on 96 groundwater samples collected in the period March-May 2021 from Holocene, Pleistocene and Neogene deposits. The results show that 58% of shallow groundwater in Wrocław was aggressive towards concrete and steel. The slight (XA1), moderate (XA2) and high (XA3) aggressiveness was characteristic for 32%, 23% and 3% of the analysed waters, respectively. The significant classification factors were the concentrations of aggressive carbon dioxide, sulphate ions and, less significant, pH. The presence of magnesium and ammonium ions in groundwater did not have any classification significance because of low concentrations. The occurrence of aggressive groundwater is associated with the environment of river sediments, mainly of Holocene and Pleistocene age. Groundwater beneath till and clay formations, mainly of Pleistocene age, and of anthropogenic banks and dumps shows significantly lower aggressiveness. Aggressiveness of groundwater sampled from the aquifer covered by Neogene clay deposit is not demonstrated. The aggressiveness of Wrocław groundwater shows a mosaic space character resulting from the geological structure of the city's subsurface formations and is probably also related to the form of land development. The most aggressive ones were associated with green, agricultural and liquidated municipal waste dump areas.
Źródło:
Przegląd Geologiczny; 2021, 69, 12; 901--908
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sedimentological study of the Nikolčice Formation : evidence of the Middle Jurassic transgression onto the Bohemian Massif (subsurface data)
Autorzy:
Nehyba, S.
Opletal, V.
Powiązania:
https://bibliotekanauki.pl/articles/2060331.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Nikolčice Formation
Middle Jurassic
provenance
shallow marine
nearshore depositional environment
Opis:
The Jurassic sedimentary succession along the eastern margin of the Bohemian Massif starts with mostly fluvial deposits of the Gresten Formation and continues after marine transgression with the deposition of the Nikolčice Formation (Middle Jurassic, Callovian). The provenance and depositional environment of the Nikolčice Formation showed that deposition occurred within offshore, transitional zone, shoreface, foreshore and littoral sand bar environments; however, shoreface and foreshore deposits dominate in the cores studied. The crystalline units along the eastern margins of the Bohemian Massif represent the primary source of deposits of the Nikolčice Formation. An important role was played by acidic and intermediate plutonites and highly metamorphosed metasedimentary rocks (granulite and amphibolite metamorphic facies), which indicates an advanced stage of erosion of the source area. The role of volcanic and intrusive rocks was small. The primary source was followed by an additional recycled source from older sedimentary rocks (especially the Moravo-Silesian Paleozoic deposits – the Líšeň Formation, the Myslejovice Formation). A similarity of the source areas for the Nikolčice Formation and the underlying Gresten Formation was recognized. Identified differences in their source areas are mainly explained by varied erosional levels due to successive exhumation of the source Variscan orogen and possibly also by an expansion of the source area.
Źródło:
Geological Quarterly; 2017, 61, 1; 138--155
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geneza krzemieni górnego oksfordu w Krzemionkach Opatowskich
Genesis of the Upper Oxfordian flints in Krzemionki Opatowskie, Poland
Autorzy:
Gutowski, P.
Pieńkowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/2077299.pdf
Data publikacji:
2004
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
krzemionka opatowska
krzemień
shallow water carbonates
decapod burrows
sedimentary discontinuities
Opis:
Early diagenetic concretionary flint nodules from the Upper Oxfordian oolitic and micritic limestones represent silicified crustacean burrows. Their occurence is confined to very shallow carbonate facies of barrier, lagoonal, and tidal flat origin. Fills of crustacean burrows commonly provided a nucleation centre for flint formation and thereby the template on which flint nodule beds were constructed. The reason for the special relationship between flint and crustacean burrows probably lie in the original texture (high permeability) of the burrow networks and also in the organic content (including the microbial assemblages) lowering the pH. Nodule horizons are developed more or less parallel to bedding, to form several widespread horizons of the regional correlative significance.
Źródło:
Volumina Jurassica; 2004, 2, 1; 29-36
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical model of acoustic wave propagation in shallow water
Autorzy:
Kozaczka, E.
Grelowska, G.
Powiązania:
https://bibliotekanauki.pl/articles/258460.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow water acoustics
propagation of acoustic waves in water layer
Opis:
The work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “deformed” by different phenomena. The acoustic field distribution in the real shallow sea is affected not only by multiple reflections, but also by stochastic changes in the free surface shape, and statistical changes in the seabed shape and impedance. The paper discusses fundamental problems of modal sound propagation in the water layer over different types of bottom sediments. The basic task in this case was to determine the acoustic pressure level as a function of distance and depth. The results of the conducted investigation can be useful in indirect determination of the type of bottom.
Źródło:
Polish Maritime Research; 2017, 2; 48-55
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact Cnoidal Solutions of the Extended KdV Equation
Autorzy:
Infeld, E.
Karczewska, A.
Rowlands, G.
Rozmej, P.
Powiązania:
https://bibliotekanauki.pl/articles/1030809.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
shallow water waves
extended KdV equation
analytic solutions
inverted cnoidal waves
Opis:
The KdV equation can be derived within the shallow water limit of the Euler equations. Over the last few decades, this equation has been extended to include both higher order effects (KdV2) and an uneven river bottom. Although this equation is not integrable and has only one conservation law, exact periodic and solitonic solutions exist for the even bottom case. The method used to find them assumes the same functional forms as for KdV solutions. The KdV2 equation imposes more constraints on the parameters of solutions. Quite unexpectedly, we found two regions in m parameter space for periodic solutions. For the range of m close to one the cnoidal waves are upright as expected, but are inverted in the m region close to zero which is a completely new feature. The properties of exact solutions for KdV and KdV2 are compared. Numerical evolution of all the discussed exact solutions to KdV2 is stable and confirms the properties of the analytic solutions.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1191-1199
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shallow Layer Convolutional Features with Correlation Filters for UAV Object Tracking
Autorzy:
Syihabuddin, Budi
Wibowo, Suryo Adhi
Prasetyo, Agus D.
Saputri, Desti Madya
Powiązania:
https://bibliotekanauki.pl/articles/2142310.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
CNN
convolutional features
correlation filter
object tracking
shallow layer
UAV tracking
Opis:
In this paper, convolutional shallow features are proposed for unmanned aerial vehicle (UAV) tracking. These convolutional shallow features are generated by pre-trained convolutional neural networks (CNN) and are used to represent the target objects. Furthermore, to estimate the location of the target objects, an adaptive correlation filter based on the Fourier transform is used. This filter is multiplied with the convolutional shallow features by using pixel-wise multiplication in the Fourier domain. Then, the inverse of Fourier is performed to estimate the location of the target object, where its location is represented by the maximum value of the response map. Unfortunately, the target object always changes its appearance during tracking. Therefore, we proposed an updated model to address this issue. The proposed method is evaluated by using the UAV123 10fps benchmark dataset. Based on the comprehensive experimental results, the proposed method performs favorably against state-of-the-art tracking algorithms.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 2; 49--57
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-dimensional modelling of wave motion in shallow-water areas
Autorzy:
Kapiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/241315.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
swash zone
shallow water
wave transformation
Lagrangian approach
two-dimensional model
Opis:
A new mathematical model for prediction of a two-dimensional wave motion in shallow water is presented herein. It can be applied to investigate shoaling, diffraction, refraction, breaking, bottom friction and wave run-up on a beach, as well as mass transport and orbital motion. The model also includes an oblique wave approach to the shore and irregular bottom topography. Such engineering constructions as seawalls, breakwaters and groins are simulated numerically. Simple results of computations, shown in graphic form, indicate possible practical applications of the model.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2004, 51, 1; 3-24
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation and Modelling on the Shipping Noise in Shallow Waters with Complex Islands and Reefs of the East China Sea
Autorzy:
Peng, Zilong
Zhou, Fulin
Fan, Jun
Wang, Bin
Wen, Huabing
Powiązania:
https://bibliotekanauki.pl/articles/1953475.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
shipping noise
spectral source level
noise mapping
shallow water
merchant ship
Opis:
The impact of the noise radiated from merchant ships on marine life has become an active area of research. In this paper, a methodology integrating observation at a single location and modelling the whole noise field in shallow waters is presented. Specifically, underwater radiated noise data of opportunistic merchant ships in the waters of Zhoushan Archipelago were collected at least one day in each month from January 2015 to November 2016. The noise data were analyzed and a modified empirical spectral source level (SSL) model of merchant ships was proposed inspired by the RANDI-3 model (Research Ambient Noise Directionality) methodology. Then combining the modified model with the realistic geoacoustic parameters and AIS data of observed merchant ships, the noise mappings in this area were performed with N × 2D of Normal Mode calculations, in which the SSL of each ship was estimated using the modified model. The sound propagation at different receiving positions is different due to the shielding effect of islands and bottom topography. The methodology proposed in this paper may provide a reference for modelling shipping noise in shallow waters with islands and reefs.
Źródło:
Archives of Acoustics; 2021, 46, 2; 301-311
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model experiments to assess effect of cavities on bearing capacity of two interfering superficial foundations resting on granular soil
Autorzy:
Saadi, Djamel
Abbeche, Khelifa
Boufarh, Rafik
Powiązania:
https://bibliotekanauki.pl/articles/1845136.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bearing capacity
shallow foundation
cavity
interference effect
model test
granular soil
Opis:
The objective of this paper is to describe the effect of cavities on the bearing capacity of two interfering footings based on granular soil using an exclusively experimental approach with a test model designed in the laboratory. The experimental protocol was carried out based on the variation of several parameters such as the spacing (x) (axis to axis) between the footings, and the distance (H) between the footings and cavities and between the cavities axes (L). The results highlight the effect of cavities and the interference of two strip footings on the bearing capacity factor (q) and efficiency factor (EF). Moreover, the results revealed that, in the case wherein the distance between the footings and the cavity is greater than 3, the cavity impact is eliminated.
Źródło:
Studia Geotechnica et Mechanica; 2020, 42, 3; 222-231
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and Modelling on Radiated Noise of a Typical Fishing Boat Measured in Shallow Water Inspired by AQUO Project’s Model
Autorzy:
Peng, Z.
Fan, J.
Wang, B.
Powiązania:
https://bibliotekanauki.pl/articles/177092.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
radiated noise
South China Sea
predicted model
shallow water
transmission loss
Opis:
The shipping noise near channels and ports is an important contribution to the ambient noise level, and the depth of these sites is often less than 100 m. However less attention has been paid to the measurement in shallow water environments (Brooker, Humphrey, 2016). This paper presents extensive measurements made on the URN (underwater radiated noise) of a small fishing boat in the South China Sea with 87 m depth. The URN data showed that the noise below 30 Hz was dominated by the background noise. The transmission loss (TL) was modelled with FEM (finite element method) and ray tracing according to the realistic environmental parameters in situ. The discrepancy between the modelled results and the results using simple law demonstrates both sea surface and bottom have significant effect on TL for the shallow water, especially at low frequencies. Inspired by the modelling methodology in AQUO (Achieve QUieter Oceans) project (Audoly et al., 2015), a predicted model applied to a typical fishing boat was built, which showed that the URN at frequencies below and above 100 Hz was dominated by non-cavitation propeller noise and mechanical noise, respectively. The agreement between predicted results and measured results also demonstrates that this modelling methodology is effective to some extent.
Źródło:
Archives of Acoustics; 2018, 43, 2; 263-273
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods to Estimate the Channel Delay Profile and Doppler Spectrum of Shallow Underwater Acoustic Channels
Autorzy:
Nguyen, Van Duc
Nguyen, Tien Hoa
Ho, Hoa Xuan Thi
Powiązania:
https://bibliotekanauki.pl/articles/176670.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
shallow underwater acoustic
channel parameters detection
channel delay profile
Doppler spectrum
Opis:
In this paper, we present the methods to detect the channel delay profile and the Doppler spectrum of shallow underwater acoustic channels (SUAC). In our channel sounding methods, a short impulse in form of a sinusoid function is successively sent out from the transmitter to estimated the channel impulse response (CIR). A bandpass filter is applied to eliminate the interference from out-of-band (OOB). A threshould is utilized to obtain the maximum time delay of the CIR. Multipath components of the SUAC are specified by correlating the received signals with the transmitted sounding pulse with its shifted phases from 0 to 2π. We show the measured channel parameters, which have been carried out in some lakes in Hanoi. The measured results illustrate that the channel is frequency selective for a Barrow band transmission. The Doppler spectrum can be obtained by taking the Fourier transform of the time correlation of the measured channel transfer function. We have shown that, the theoretical maximum Doppler frequency fits well to that one obtained from measurement results.
Źródło:
Archives of Acoustics; 2019, 44, 2; 375-383
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przestrzenna i czasowa zmienność stężenia azotanów w płytkich wodach gruntowych w miejscu lokalizacji polowej pryzmy obornika
Spatial and temporal variability of nitrates concentration in shallow groundwater at the field location of the manure heap
Autorzy:
Pietrzak, S.
Rossa, L.
Marcinkowski, T.
Wojcieszak, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/401579.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
azotany
wody gruntowe
polowa pryzma obornika
nitrates
shallow groundwater
field manure heap
Opis:
Płytkie wody podziemne są szczególnie podatne na zanieczyszczenie azotanami pochodzenia rolniczego. W pracy podjęto próbę rozpoznania kierunku przestrzennych i czasowych zmian stężenia azotanów w płytkich wodach gruntowych, zalegających pod warstwą piaszczystej gleby, w miejscu okresowego składowiska obornika i w jego najbliższym otoczeniu. Badania przeprowadzono w latach 2009–2015 na terenie gospodarstwa rolnego ukierunkowanego na produkcję mleka, położonego w północno-zachodniej części środkowego basenu Biebrzy, w województwie podlaskim. Stanowisko badawcze zlokalizowano na skraju pola, na którym corocznie uprawiano kukurydzę i gdzie na przełomie lat 2010/2011 i 2014/2015 okresowo składowano obornik. Próbki wód gruntowych pobierano korzystając z 7 studzienek kontrolno-pomiarowych, w odstępach miesięcznych, 4-8 razy w roku. Uzyskane zbiory wyników zawartości azotanów poddano analizie statystycznej z wykorzystaniem analizy wariancji z testem Kruskala-Wallisa. Przeprowadzono również analizę korelacji stężenia azotu azotanowego w wodzie z różnych punktów badawczych oraz analizę jego regresji w kolejnych latach badań. Średnie, roczne stężenie azotu azotanowego w próbkach wód gruntowych pobieranych z poszczególnych studzienek kształtowało się szerokim zakresie wartości od 1,1 do 101,8 mg N-NO3∙dm–3. W zdecydowanej większości przypadków (86%) wielokrotnie przekraczało ono graniczną wartość dla III klasy jakości wód podziemnych czyli 11,3 mg N-NO3∙dm–3. Zatem badane wody należy zaliczyć do wód zanieczyszczonych bądź zagrożonych zanieczyszczeniem. Ponad to w ujęciu przestrzennym i czasowym, średnie, roczne zawartości azotanów w badanych próbach wód gruntowych, pobieranych ze studzienek zainstalowanych na terenie stanowiska badawczego charakteryzowały się znacznym zróżnicowanym przestrzennym, miały odmienne nasilenie jak też kierunki zmian w czasie, w niewielkim stopniu były ze sobą skorelowanie.
Shallow groundwater is particularly susceptible to contamination by nitrates from agricultural sources. The paper attempts to recognize the direction of spatial and temporal changes in the concentration of nitrates in shallow groundwater, lying under a layer of sandy soil, in the place of a temporary manure storage place and in its immediate vicinity. The study was conducted in the years 2009–2015 on farm focused on milk production, located in the north-western part of the central basin of Biebrza, in Podlaskie voivodeship . The research stand was located at the edge of the field where maize was grown every year and where manure was periodically stored at the turn of 2010/2011 and 2014/2015. Groundwater samples were collected using 7 control and measurement wells, on a monthly basis, 4-8 times a year. The obtained results of nitrates content were subjected to statistical analysis using the analysis of variance with the Kruskal-Wallis test. The analysis of correlation of nitrate nitrogen concentration in water from various research points and analysis of its regression in subsequent years of research was also performed. The average annual concentration of nitrate nitrogen in groundwater samples collected from individual wells was in the wide range from 1.1 to 101.8 mg NO3∙dm–3. In the vast majority of cases (86%) it repeatedly exceeded the limit value for the third class of groundwater quality, or 11.3 mg N-NO3∙dm–3. Thus, the tested water should be classified as polluted or at risk of contamination. In addition, in spatial and temporal terms, the average annual nitrates content in the tested groundwater samples collected from wells installed on the research site was characterized by a significant different spatial, has a different intensity as well as directions of changes in time, to a small extent correlated with each other.
Źródło:
Inżynieria Ekologiczna; 2018, 19, 5; 75-82
2081-139X
2392-0629
Pojawia się w:
Inżynieria Ekologiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Miękka podkładka pod centralną częścią fundamentu bezpośredniego elektrowni wiatrowej
Soft comprehesive layer under the central part of wind turbine shallow foundations
Autorzy:
Dołżyk, K.
Szypcio, Z.
Chmielewska, I.
Powiązania:
https://bibliotekanauki.pl/articles/402709.pdf
Data publikacji:
2013
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
elektrownie wiatrowe
fundamenty bezpośrednie
obciążenie wiatrem
wind turbines
shallow foundations
wind load
Opis:
W pracy omówiono niektóre problemy fundamentowania bezpośredniego elektrowni wiatrowych. Elektrownie wiatrowe są bardzo specyficznymi budowlami. Główne siły przekazywane na fundament są wywołane działaniem wiatru. Wiatr wieje o różnej sile z różnych kierunków, zatem fundament musi mieć dużą sztywność. Zwykle fundamentem jest płyta kołowa o różnej grubości i średnicy kilkunastu metrów. W pracy wykazano, że celowym jest wykonanie miękkiej podkładki w centralnej części fundamentu, znacząco eliminującej różnice osiadań nieodwracalnych części środkowej i brzegów fundamentu. Miękka podkładka o promieniu mniejszym niż 0,3 promienia fundamentu nie zmniejsza jego nośności i sztywności na obrót.
The paper discusses some problems relating to shallow foundations of wind turbines. Wind turbines are very specific buildings. Main actions transmitted onto foundations are produced by wind. The power of wind varies as it blows from different directions and at a different speed so the foundation must be very stiff. Usually, the foundation is a circular plate of different thickness and a diameter of more than ten meters. It has been shown in this study that it is reasonable to build soft compressive material under the central part of the foundation. The compressive material significantly eliminates irreversible settlement differences of the center and edge of the foundation. The soft compressive material which radius is smaller than 0.3 of foundation radius does not reduce its bearing capacity and rotational stiffness.
Źródło:
Budownictwo i Inżynieria Środowiska; 2013, 4, 3; 193-197
2081-3279
Pojawia się w:
Budownictwo i Inżynieria Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical model of forecasting the formation of sinkhole using Salustowicz’s theory
Model matematyczny prognozowania zapadlisk przy wykorzystaniu teorii sklepienia ciśnień Sałustowicza
Autorzy:
Strzałkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/219816.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rock mechanics
shallow caverns
predicting sinkholes
mechanika górotworu
prognozowanie zapadlisk
płytkie pustki
Opis:
In area affected by old, shallow extraction in some cases sinkholes are formed, causing security issues in urbanized areas. Problem of working out deterministic forecast of this threat seems to be important and up-to-date. Mathematical model presented in this work let us predict the possibility of sinkhole formation. That prediction is essential for analyzing possibility of investments in such areas. Basing on presented work, it is also possible to determine dimensions of sinkhole. Considerations are based on known from literature Sałustowicz’s theory, which is utilises Huber’s solution of equation describing the stress state around elliptic void made in flat plate.
Początki eksploatacji górniczej na Górnym Śląsku sięgają XVIII stulecia. Dawna eksploatacja prowadzona na głębokościach nie przekraczających 80 m, do dziś generuje zagrożenia bezpieczeństwa powszechnego z uwagi na możliwość wystąpienia zapadlisk. Jak to wynika z pracy (Chudek i in., 2013), obszary pod którymi prowadzono w minionych latach płytką eksploatację zajmują znaczną powierzchnię śląskich miast, które w dalszym ciągu się rozbudowują. Dlatego problem występowania zapadlisk należy w dalszym ciągu uznać za ważny i aktualny. Duża liczba zapadlisk, ze zrozumiałych względów, jest wynikiem utraty stateczności płytkich wyrobisk korytarzowych. Istniejące metody prognozowania zapadlisk pozwalają głównie określać prawdopodobieństwo wystąpienia zapadliska. Jeśli wartość prawdopodobieństwa wystąpienia zapadliska jest większa od 0, wówczas należy się liczyć z zagrożeniem bezpieczeństwa terenu i co istotniejsze ludności. Taki sposób prognozowania wystąpienia zapadlisk nie daje jednoznacznej odpowiedzi na pytanie, czy teren objęty analizą jest rzeczywiście zagrożony. Dlatego istotnym jest stworzenie możliwości deterministycznego prognozowania tego typu deformacji. W tym kierunku zmierza propozycja autora pracy, w której wykorzystano teorię sklepienia ciśnień (Sałustowicz, 1956). Teoria ta znakomicie nadaje się do tego celu, gdyż jako jedyna z wielu w tym zakresie pozwala określić, czy pustka związana z wyrobiskiem znajduje się w stanie stateczności. Znane są bowiem przypadki, gdy płytkie wyrobiska górnicze, bez obudowy przez wiele lat pozostają w stanie nienaruszonym. W ramach pracy dokonano szczegółowych obliczeń pola strefy odprężonej nad wyrobiskiem, bez stosowania uproszczeń przyjętych przez autora metody. Stosując podobne założenia jak w innych, znanych z literatury rozwiązaniach, podano warunki, mówiące o tym kiedy gruzowisko skalne zapełni szczelnie pustkę, bez powstania pustki wtórnej, a kiedy pustka wtórna powstanie. Zależy to od wymiarów i głębokości lokalizacji pustki oraz własności górotworu nad pustką. Warunkiem wystąpienia zapadliska jest aby strefa odprężona, związana z pustką pierwotną lub wtórną osiągnęła wysokość, przy której obejmować będzie nadkład, zbudowany ze skał luźnych. W dalszej kolejności zaproponowano wzory umożliwiające określenie wymiarów zapadlisk. Wyróżniono przy tym dwa przypadki: gdy strop pustki osiąga spąg nadkładu – wzór (15), gdy strefa odprężona obejmuje swym zasięgiem luźne skały nadkładu – wzór (19). Dalszym etapem badań prowadzonych przez autora jest sformułowanie warunków, pozwalających stwierdzić, kiedy eksploatacja górnicza prowadzona pod pustką może wywołać jej samopodsadzenie, a w konsekwencji spowodować powstanie zapadliska na powierzchni. Prowadzone są również prace związane z utworzeniem oprogramowania komputerowego, wykorzystującego podane wzory i z weryfikacją rozwiązania w oparciu o przypadki znane z praktyki górniczej.
Źródło:
Archives of Mining Sciences; 2015, 60, 1; 63-71
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekologia głęboka a edukacja. W poszukiwaniu nowego paradygmatu
Deep Ecology and Education: Searching for a New Reference Point
Autorzy:
Nawrocki, Radosław
Powiązania:
https://bibliotekanauki.pl/articles/2149062.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet w Białymstoku. Wydział Pedagogiki i Psychologii
Tematy:
ekologia głęboka
płytka ekologia
antropocentryzm
Arne Naess
deep ecology
shallow ecology
anthropocentrism
Opis:
Celem niniejszego tekstu jest przedstawienie podstawowych założeń tzw. głębokiej ekologii. Twierdzę, że skrupulatne i uważne wyciągnięcie wniosków z tej koncepcji może stać się ważnym i inspirującym punktem odniesienia dla edukacji. Chodzi tu zarówno o dyskursy pedagogiczne, jak i praktykę edukacyjną. Głęboka ekologia zawiera w sobie odmienną od najbardziej utrwalonej w kulturze zachodniej koncepcję człowieka oraz jego miejsca w świecie. Odmienność ta związana jest z definiowaniem człowieka i jego relacji ze światem, powinnościami wobec środowiska, sposobem myślenia, strategią budowania tożsamości. To istotnie wpływa na koncepcję edukacji, jaką przyjmujemy.
The purpose of this text is to present the basic assumptions of deep ecology. In my view, meticulous and careful drawing of conclusions from this concept can become an important and inspiring reference point for education, both in terms of pedagogical discourses and educational practice. Deep ecology involves a concept of human and their place in the world different from the majority of concepts well-established in the Western culture. This difference is related to the definition of human and their relationship with the world, obligations towards the environment, way of thinking, and strategy of building identity. This significantly affects the concept of education that we adopt.
Źródło:
Parezja. Czasopismo Forum Młodych Pedagogów przy Komitecie Nauk Pedagogicznych PAN; 2019, 1(11); 30-42
2353-7914
Pojawia się w:
Parezja. Czasopismo Forum Młodych Pedagogów przy Komitecie Nauk Pedagogicznych PAN
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ranking of the utility of selected geostatistical interpolation methods in conditions of highly skewed seismic data distributions: a case study of the Baltic Basin (Poland)
Ranking przydatności wybranych metod interpolacji geostatystycznej w warunkach silnie skośnych rozkładów danych sejsmicznych: studium przypadku Basenu Bałtyckiego (Polska)
Autorzy:
Sowińska-Botor, Justyna
Mastej, Wojciech
Maćkowski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/27311659.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
seismic data
data processing
shallow subsurface
dane sejsmiczne
przetwarzanie danych
strefa przypowierzchniowa
Opis:
The suitability of several low-labor geostatistical procedures in the interpolation of highly positively skewed seismic data distributions was tested in the Baltic Basin. These procedures were a combination of various estimators of the model of spatial variation (theoretical variogram) and kriging techniques, together with the initial data transformation to normal distribution or lack thereof. This transformation consisted of logarithmization or normalization using the anamorphosis technique. Two variations of the theoretical variogram estimator were used: the commonly used classical Matheron estimator and the inverse covariance estimator (InvCov), which is robust with regard to non-ergodic data. It was expected that the latter would also be resistant to strongly skewed data distributions. The kriging techniques used included the commonly used ordinary kriging, simple kriging useful for standardized data and the non-linear median indicator kriging technique. It was confirmed that normalization (anamorphosis) is the most useful and less laborious geostatistical procedure of those suitable for such data, which results in a standardized normal distribution. The second, not obvious statement for highly skewed data distributions suggests that the non-ergodic inverted covariance (InvCov) estimator of variogram has an advantage over the Matheron’s estimator. It gives a better assessment of the C0 (nugget effect) and C (sill) parameters of the spatial variability model. Such a conclusion can be drawn from the fact that the higher the estimation of the relative nugget effect L = C0/(C0 + C) using the InvCov estimator, the weaker the correlation between the kriging estimates and the observed values. The values of the coefficient L estimates obtained by using the Matheron’s estimator do not meet this expectation.
W ramach studium przypadku w rejonie basenu bałtyckiego przetestowano przydatność kilku mało pracochłonnych procedur geostatystycznych do interpolacji silnie skośnych rozkładów danych sejsmicznych. Były one kombinacją różnych estymatorów modelu zmienności przestrzennej (wariogramu teoretycznego) i technik krigingu, wraz ze wstępną transformacją danych do rozkładu normalnego lub jej brakiem. Transformacja ta polegała na logarytmowaniu bądź na normalizacji z użyciem techniki anamorfozy. Zastosowano dwie odmiany estymatora wariogramu teoretycznego: powszechnie stosowany klasyczny estymator Matherona oraz estymator odwróconej kowariancji (InvCov) odporny na dane nieergodyczne. Spodziewano się, że ten drugi okaże się również odporny na silnie skośne rozkłady dane. Wśród zastosowanych technik krigingu znalazł się powszechnie stosowany kriging zwyczajny, kriging prosty użyteczny dla danych zestandaryzowanych i nieliniowa technika krigingu wskaźnikowego. Najbardziej użyteczną i mało pracochłonną procedurą geostatystyczną, nadającą się do zastosowania w przypadku takich danych, okazała się normalizacja (anamorfoza), w efekcie której uzyskuje się rozkład normalny standaryzowany. Drugim, nieoczywistym wnioskiem dla silnie skośnych rozkładów danych, jest sugestia, iż estymator InvCov ma przewagę nad estymatorem Matherona, ponieważ pozwala na bardziej realistyczną ocenę parametrów C0 (efektu samorodka) i C (wariancji progowej) modelu zmienności przestrzennej. Taki wniosek można wyciągnąć z faktu, że im wyższa wartość relatywnego efektu samorodków L = C0/(C0 + C) obliczona za pomocą estymatora InvCov, tym słabsza korelacja między wartościami obliczonymi a danymi. Wartości współczynnika L obliczone za pomocą estymatora Matherona nie posiadają tej właściwości.
Źródło:
Gospodarka Surowcami Mineralnymi; 2023, 39, 3; 149--172
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Two-dimensional Numerical Model of Heat Exchange in the Soil Massif During the Operation of a Shallow Horizontal Soil Heat Exchanger
Autorzy:
Basok, Boris
Pavlenko, Anatoliy
Nedbailo, Oleksandr
Bozhko, Ihor
Moroz, Maryna
Powiązania:
https://bibliotekanauki.pl/articles/30145705.pdf
Data publikacji:
2023
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
shallow horizontal soil heat exchanger
heat flux
numerical modelling
renewable energy sources
Opis:
The current article uses a two-dimensional numerical model to represent the results of theoretical studies of the heat exchange in the soil massif during the operation of a shallow horizontal soil heat exchanger. The analysis of literature sources showed that one of the important conditions for the effective operation of a shallow-soil heat exchange is its rational design parameters, such as the total length of the pipeline, the diameter of the pipe, the distance between the axis of the adjacent pipes, the depth of the heat exchanger placement, etc. A two-dimensional heat exchange model in the soil mass was developed, which made it possible to investigate the operation of a shallow horizontal soil heat exchanger. It was found that the step between the axis of the adjacent pipes of the multi-loop heat exchanger, which is 0.95 m, is optimal when creating a shallow horizontal soil heat exchanger in the soil conditions of Kyiv.
Źródło:
Rocznik Ochrona Środowiska; 2023, 25; 274-281
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Galveston Bay dynamics under different wind conditions
Autorzy:
Salas-Monreal, D.
Anis, A.
Salas-de-Leon, D.A.
Powiązania:
https://bibliotekanauki.pl/articles/48132.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
suspended particle
dispersion
shallow estuary
Galveston Bay
dynamics
wind condition
marine ecosystem
Źródło:
Oceanologia; 2018, 60, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seasonal variations in the abundance and sinking flux of biogenic silica in Daya Bay, Northern South China Sea
Autorzy:
Zhao, X.
Yang, W.
Ma, H.
Li, J.
Chen, M.
Fang, Z.
Zhang, X.
Zeng, J.
Qiu, Y.
Zheng, M.
Powiązania:
https://bibliotekanauki.pl/articles/48777.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
biogenic silica
flux
thorium
seasonal variation
shallow water
Daya Bay
China Sea
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metody AHP do oceny reprezentatywności studzien głębinowych pierwszego poziomu wodonośnego
The application of AHP for validity of shallow groundwater wells
Autorzy:
Kachnic, M.
Powiązania:
https://bibliotekanauki.pl/articles/2063150.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
pierwszy poziom wodonośny
reprezentatywność studzien
AHP
IDRISI
shallow groundwater
validity of wells
Opis:
W pracy wykorzystano metodę AHP w celu analizy reprezentatywności studzien w rejonie Unisławia, w których rozpoznano pierwszy poziom wodonośny. Do oceny reprezentatywności studzien przyjęto następujące kryteria: informacje o występowaniu lub braku warstwy wodonośnej, wydajność jednostkowa, rodzaj przeprowadzonej weryfikacji terenowej studzien i możliwość weryfikacji informacji o punkcie badawczym poprzez aktualny stan fizyczny studni. Wybrane kryteria nie zapewniają pełnej oceny wszystkich punktów opróbowania pierwszego poziomu wodonośnego (Ppw) pod kątem ich przydatności do wyznaczenia zasięgu Ppw. Wypracowanie metodyki oceny reprezentatywności i wiarygodności punktów rozpoznania hydrogeologicznego jest pierwszym etapem do opracowania rankingu informacji zamieszczonych na mapach hydrogeologicznych. Opracowany ranking punktów można odnieść do jednostki obszarowej, w której one występują, a następnie ocenić statystycznie, czy punkty te w wystarczającym stopniu spełniają wymogi, jakie zostaną ustalone dla badanej jednostki obszarowej. Procedury obliczeniowe realizowano w programie IDRISI.
The AHP method was used for the simplified assessment of validity of wells from the Unisław area in Poland. Validity of wells is the degree of belief of wells which were used for evaluation of the area where shallow groundwater exists. To establish the degree of belief of wells, information about the top and bottom of the aquifer, technical conditions of wells and aquifer yield were used.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2009, 436, z. 9/1; 199-203
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effectiveness Analysis of Rolling Bearing Fault Detectors Based On Self-Organising Kohonen Neural Network – A Case Study of PMSM Drive
Autorzy:
Jankowska, Kamila
Ewert, Pawel
Powiązania:
https://bibliotekanauki.pl/articles/1955971.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
PMSM
rolling bearing
electric drive diagnostics
self-organising map
shallow neural network
Opis:
Due to their many advantages, permanent magnet synchronous motors (PMSMs) are increasingly used in not only industrial drive systems but also electric and hybrid vehicle drives, aviation and other applications. Unfortunately, PMSMs are not free from damage that occurs during their operation. It is assumed that about 40% of the damage that occurs is related to rolling bearing damage. This article focuses on the use of Kohonen neural network (KNN) for rolling bearing damage detection in a PMSM drive system. The symptoms from the fast Fourier transform (FFT) and Envelope (ENV) Analysis of the mechanical vibration acceleration signal were analysed. The signal ENV was obtained by applying the Hilbert transform (HT). Two neural network functions are discussed: a detector and a classifier. The detector detected the damage and the classifier determined the type of damage to the rolling bearing (undamaged bearing, damaged rolling element, outer or inner race). The effectiveness of the analysed networks from the point of view of the applied signal processing method, map size, type of neighbourhood radius, distance function and the influence of input data normalisation are presented. The results are presented in the form of a confusion matrix, together with 2D and 3D maps of active neurons.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 100-112
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coniacian-?Santonian paralic sedimentation in the Rakowice Małe area of the North Sudetic Basin, SW Poland: sedimentary facies, ichnological record and palaeogeographical reconstruction of an evolving marine embayment
Autorzy:
Leszczyński, S.
Powiązania:
https://bibliotekanauki.pl/articles/191916.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
shallow marine
paludal
lagoonal
brackish enironments
bioturbation
ichnofossils
Cretaceous
Lower Silesia
Polska
Opis:
The Coniacian-?Santonian siliciclastic succession outcropped in a sandstone quarry at Rakowice Małe (Żerkowice Member of the Rakowice Wielkie Formation, and the Czerna Formation including the Nowogrodziec Member; North Sudetic Basin, SW Poland) provides an interesting example of paralic deposits. Lithofacies and ichnofossil examination indicate coastal, lacustrine, paludal and lagoonal sedimentation. Valuable new data are supplied by trace fossils, a feature not considered yet in the literature on the Upper Cretaceous of the North Sudetic Basin. Trace fossils are overall abundant in the upper part of the Nowogrodziec Member and overlying part of the Czerna Formation. The following ichnogenera: Thalassinoides, Ophiomorpha, Asterosoma, Palaeophycus, Planolites, Skolithos, Teredolites, Chondrites, Cylindrichnus, Arenicolites, Rosselia, Teichichnus, Phycodes, Phycosiphon, and Schaubcylindrichnus are represented. The trace fossils represent the Skolithos, Teredolites and Cruziana ichnofacies. The Cruziana Ichnofacies is typified by the richest trace fossil assemblage characteristic of its archetypal, proximal and stressed expressions. An upper shoreface to foreshore origin of these sediments is documented using lithofacies and the ichnofossils Ophiomorpha and Thalassinoides in the exposed part of the Żerkowice Member. Dominance of kaolinite, lack of burrows and upward passage into paludal deposits is interpreted to indicate a lacustrine origin of variegated clayey mudstone at the base of the Nowogrodziec Member. The changes of depositional environments are interpreted as resulting from separation of the area from the open sea by a sand barrier formed due to the termination of the forced regression. Siltstones containing plant roots and fragments of drifted wood showing the trace fossil Teredolites clavatus, together with coal-seams containing Thalassinoides isp., are assigned to indicate a coastal plain, paludal deposition of the overlying part of the Nowogrodziec Member and incursion of marine waters. The fining upward sequence constituting the top part of the Nowogrodziec Member and showing almost archetypal Cruziana Ichnofacies substituted by its expression indicative of highly stressed, brackish conditions are shown to indicate extensive drowning of the area and lagoonal sedimentation. Termination of the drowning, embodied in a maximum flooding surface, is indicated in a bed of coaly mudstone at the top of the Nowogrodziec Member. Sedimentation on a periodically prograded brackish bay shoreface is inferred from lithofacies, ichnofossils and body fossils for the deposits overlying the Nowogrodziec Member and topping the examined succession. The trace fossils indicate Cruziana Ichnofacies and Skolithos Ichnofacies in the expression of slightly stressed environ- ments. The whole examined part of the Czerna Formation is interpreted as a fifth-order transgressive-regressive cycle.
Źródło:
Annales Societatis Geologorum Poloniae; 2010, 80, No 1; 1-24
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Underwater Noise Generated by a Small Ship in the Shallow Sea
Autorzy:
Grelowska, G.
Kozaczka, E.
Kozaczka, S.
Szymczak, W.
Powiązania:
https://bibliotekanauki.pl/articles/177360.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal processing
sound propagation
underwater ship noise
propagation in the shallow sea
Opis:
Study of the sea noise has been a subject of interest for many years. The first works in this scope were published at the turn of the twentieth century by Knudsen (Knudsen et al., 1948) and G. Wenz (Wenz, 1962). Disturbances called “shipping noise” are one of the important components of the sea noise. In this work the results of an experimental research of underwater noise produced by a small ship of a classic propulsion are presented. A linear receiving antenna composed of two orthogonal components was used in the investigation. Identification of the main sources of acoustic waves related with the ship was achieved. In addition, the intensity of the wave was measured. The research was performed in conditions of the shallow sea.
Źródło:
Archives of Acoustics; 2013, 38, 3; 351-356
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metody płytkiej refrakcji sejsmicznej do określania własności fizycznych warstw czwartorzędowych
Application of the method of shallow seismic refraction in determining physical properties of Quaternary strata
Autorzy:
Siata, R.
Powiązania:
https://bibliotekanauki.pl/articles/340286.pdf
Data publikacji:
2003
Wydawca:
Główny Instytut Górnictwa
Tematy:
płytka refrakcja sejsmiczna
badania refrakcyjne
granice litologiczne
shallow seismic refraction
refraction
lithological boundaries
Opis:
Metodę płytkiej refrakcji stosuje się standardowo do obliczania granic litologicznych. W artykule przedstawiono możliwość jej dodatkowego wykorzystania do obliczania stałych materiałowych. Na podstawie wykonanych badań obliczono dynamiczne moduły sprężystości dla utworów czwartorzędowych, wykształconych w postaci piasków (suchych i zawodnionych), gliny i iłu. Najmniejsze wartości prędkości propagacji fal sejsmicznych stwierdzono w piaskach suchych (VP-Ą\Q m/s, V, = 280 m/s), te same piaski ale zawodnione (poniżej poziomu zwierciadła wód gruntowych) charakteryzowały się prędkościami: Vf = 1600-2000 m/s, V, = 500-600 m/s. Nieco większe prędkości (w stosunku do suchych piasków) zanotowano w przypadku glin: Vp = 700 m/s, V, = 500 m/s.
The method of shallow refraction is commonly used to determine the lithological boundaries. The paper presents the possibility of its additional application to determine the material constants. On the basis of performed investigations, the dynamic module of elasticity were detonated for Quaternary formations, developed in the form of sands (dry and watered), clay and silt. The lowest values of propagation velocity of seismic waves were found in the dry sands Vp = 410 m/s, V,- 280 m/s). The same sands, but watered, (below the underground water table) were characterized by the velocities Vp = 1600-2000 m/s, V, - 500-600 m/s. Slightly higher velocities (B relation to those of dry sands) were recorded in the case of clays Vp = 700 m/s, V, - 500 m/s.
Źródło:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa; 2003, 4; 43-50
1643-7608
Pojawia się w:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The species diversity of rotifers [Rotifera] of differentiated macrophyte habitats of Lake Budzynskie
Roznorodnosc gatunkowa wrotkow [Rotifera] zroznicowanych siedlisk makrofitow jeziora Budzynskiego
Autorzy:
Kuczynska-Kippen, N.
Powiązania:
https://bibliotekanauki.pl/articles/878592.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu
Tematy:
lake
zooplankton
Rotifera
Polska
macrophyte habitat
species diversity
Lake Budzynskie
shallow lake
rotifer
Źródło:
Roczniki Akademii Rolniczej w Poznaniu. Botanika-Steciana; 2005, 09
1896-1908
Pojawia się w:
Roczniki Akademii Rolniczej w Poznaniu. Botanika-Steciana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie tomografii elektrooporowej do lokalizacji płytkich pustek w górotworze
The use of electrical resistivity tomography for identification of shallow voids inside the rock mass
Autorzy:
Ścigała, R.
Szafulera, K.
Kruczkowski, M.
Tomiczek, K.
Powiązania:
https://bibliotekanauki.pl/articles/112524.pdf
Data publikacji:
2017
Wydawca:
STE GROUP
Tematy:
deformacje nieciągłe
płytka eksploatacja
metoda elektrooporowa
discontinuous deformations
shallow extraction
electrical resistivity method
Opis:
Warunkiem koniecznym do powstawania na powierzchni zapadlisk jest istnienie pustek w górotworze występujących na niewielkich głębokościach. Pustki te mogą być pochodzenia naturalnego (np. zjawiska krasowe) lub antropogenicznego (wskutek dokonanej eksploatacji górniczej). Bez względu na charakter powstania pustki, stanowi ona poważne zagrożenie dla szeroko rozumianego bezpieczeństwa publicznego, z uwagi na zagrożenie wystąpienia deformacji nieciągłych. Aby zagrożenie tego typu można było zlikwidować, niezbędne jest najpierw rozpoznanie lokalizacji pustki, a następnie jej likwidacja, np. poprzez wypełnienie odpowiednim materiałem. Jednym ze sposobów określenia lokalizacji płytkich pustek w górotworze w sposób nieniszczący są metody geofizyczne. W artykule przedstawiony został przykład wykorzystania jednej z metod geofizycznych – tomografii elektrooporowej, do lokalizacji płytkich antropogenicznych pustek w górotworze. Przeprowadzone badania dotyczyły terenu górniczego jednej z kopalń GZW, gdzie w przeszłości na niedużej głębokości prowadzono roboty górnicze. Teren ten wybrano ze względu na stosunkowo dobrze rozpoznaną sytuację geologiczną i górniczą, ale przede wszystkim przez wzgląd na makroskopowo zauważalne zmiany rzeźby terenu korespondujące z lokalizacją wyrobisk górniczych określonych na podstawie map górniczych oraz stwierdzone w przeszłości przez służby kopalni zapadlisko.
The necessary condition for sinkhole creation on the surface there is a void occurrence inside the rock mass, located at shallow depths. Such voids may be of natural (eg. karst phenomena) or anthropogenic origin (as an effect of underground mining works). Whatever the nature of the void is, it creates a serious threat to the broadly understood public safety, due to the risk of discontinuous deformations. For this type of threat to be eliminated, it is necessary to precisely recognize the location of the void firstly, then its liquidation should be done, eg. by filling in with appropriate material. One of the non-destructive ways for determination of the shallow cavities location inside the rock mass are geophysical methods. In the paper, an example of using the electrical resistivity tomography for identification of shallow anthropogenic voids has been presented. The study concerns the mining area of one of the Upper Silesian Basin mines, where in the past the mining works were carried out at shallow depth. This area was chosen because of the relatively well-recognized geological and mining situation, but above all for the sake of macroscopically visible changes in the terrain morphology, corresponding to the location of the mine workings identified on the basis of mining maps and the sinkhole created in the past in this area.
Źródło:
Systemy Wspomagania w Inżynierii Produkcji; 2017, 6, 3; 249-256
2391-9361
Pojawia się w:
Systemy Wspomagania w Inżynierii Produkcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of Flood Wave Propagation with Wet-dry Front by One-dimensional Diffusive Wave Equation
Autorzy:
Gąsiorowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/241192.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
diffusive wave equation
shallow water equations
overland flow
floodplain inundation
finite element method
Opis:
A full dynamic model in the form of the shallow water equations (SWE) is often useful for reproducing the unsteady flow in open channels, as well as over a floodplain. However, most of the numerical algorithms applied to the solution of the SWE fail when flood wave propagation over an initially dry area is simulated. The main problems are related to the very small or negative values of water depths occurring in the vicinity of a moving wet-dry front, which lead to instability in numerical solutions. To overcome these difficulties, a simplified model in the form of a non-linear diffusive wave equation (DWE) can be used. The diffusive wave approach requires numerical algorithms that are much simpler, and consequently, the computational process is more effective than in the case of the SWE. In this paper, the numerical solution of the one-dimensional DWE based on the modified finite element method is verified in terms of accuracy. The resulting solutions of the DWE are compared with the corresponding benchmark solution of the one-dimensional SWE obtained by means of the finite volume methods. The results of numerical experiments show that the algorithm applied is capable of reproducing the reference solution with satisfactory accuracy even for a rapidly varied wave over a dry bottom.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 3-4; 111--125
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of rapidly varied water flow in the "Wild River" type water slide
Autorzy:
Burzyński, K.
Szydłowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/241412.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
rapidly varied flow
water slide
mathematical modelling
shallow water equations
finite volume method
Opis:
The numerical analysis of the water flow along the 'Wild River' type water slide is presented. As the mathematical model of the free surface flow shallow water equations are assumed. In order to solve the equations, when transient, rapidly varied flow is present, the numerical scheme based on finite volume method is applied. The numerical simulation of water slide flow is computed on unstructured, triangular mesh. The results of calculation are examined against flow parameters observed on the real object installed in water park in Sopot. Generally good agreement between measured and calculated results was observed. Moreover, the calculations are compared to experimental data available due to physical modelling. As the similarity between physical phenomena of flow within water slide and in the river valley after dam-break event is observed, the investigation was realized within the framework of the State Committee for Scientific Research 6P06S04121 project.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 1; 37-57
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The endemic radiodonts of the Cambrian Stage 4 Guanshan Biota of South China
Autorzy:
Jiao, D.-G.
Pates, S.
Lerosey-Aubril, R.
Ortega-Hernandez, J.
Yang, J.
Lan, T.
Zhang, X-G.
Powiązania:
https://bibliotekanauki.pl/articles/2082327.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Amplectobeluidae
Anomalocarididae
Tamisiocarididae
Paranomalocaris
Burgess Shale-type exceptional
preservation
shallow water
Cambrian
China
Opis:
The Guanshan Biota (South China, Cambrian, Stage 4) contains a diverse assemblage of biomineralizing and non-biomineralizing animals. Sitting temporally between the Stage 3 Chengjiang and Wuliuan Kaili Biotas, the Guanshan Biota contains numerous fossil organisms that are exclusive to this exceptional deposit. The Guanshan Konservat-Lagerstätte is also unusual amongst Cambrian strata that preserve non-biomineralized material, as it was deposited in a relatively shallow water setting. In this contribution we double the diversity of radiodonts known from the Guanshan Biota from two to four, and describe the second species of Paranomalocaris. In addition, we report the first tamisiocaridid from South China, and confirm the presence of a tetraradial oral cone bearing small and large plates in “Anomalocaris” kunmingensis, the most abundant radiodont from the deposit. All four radiodont species, and three genera, are apparently endemic to the Guanshan Biota. When considered in the wider context of geographically and temporally comparable radiodont faunas, endemism in Guanshan radiodonts is most likely a consequence of the shallower and more proximal environment in which they lived. The strong coupling of free-swimming radiodonts and benthic communities underlines the complex relationship between the palaeobiogeographic and environmental distributions of prey and predators. This local adaptation of radiodonts to their prey is highlighted by the frontal appendage morphology of the two species of Paranomalocaris, apparently specialised to different feeding modes, while the recognition of the limited geographic range of some radiodont faunas highlights the importance of exploring as many deposits as possible to fully understand this group.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 2; 255-274
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of tectonic setting on groundwater chemical composition in the Peshkopi gypsum karst area, Korab Mountains, Eastern Albania
Autorzy:
Eftimi, Romeo
Andreychouk, Viacheslav
Niedoba, Tomasz
Różkowski, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/31342964.pdf
Data publikacji:
2023
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
gypsum karst
groundwater shallow
deep circulation systems
water chemical composition
thermal springs
Albania
Opis:
The diversity of groundwater chemistry in the Peshkopi gypsum karst area may be related to its setting within the tectonically active Korab Massif (Albania), as shown by field tests of temperature, pH, Eh and EC, and sampling of the waters for chemical analysis (both major and trace components) from cool brackish springs and mineralized thermal springs. The relationship between the chemical composition of the spring waters and of the reservoir rocks was elucidated by analysis of anhydrite-gypsum rocks and experimental dissolution of an anhydrite-gypsum sample. Statistical analysis was used in the processing of hydrochemical data. Comparison of analytical results from 2019 with earlier data indicates compositional stability of the groundwaters over time. Our results together with statistical analysis of the hydrochemical data support an earlier hypothesis of two systems of groundwater circulation within the anhydrite-gypsum deposits of the Peshkopi region. A shallow circulation system involves cold (10-14°C), mainly brackish SO4-Ca waters with very low concentrations of Na+ and Cl- ions, reflecting their formation in a sulphate rock environment that probably corresponds spatially with a gypsum layer formed by hydration of anhydrite in the near-surface zone. A deep circulation system conditioned, inter alia, by the presence of a large fault, brings to the surface water at up to 44°C, saturated with H2S, mineralized, of the SO4-Ca type with an increased content of Na, K, HCO3, Cl, BO3 and SiO2>/sub>. The chemical composition of these waters, regardless of the presence of large amounts of sulphates, is significantly different and suggests the influence of other factors on their formation, such as slow circulation, contact with flysch rocks in the fault zone and the mixing of deep and near-surface waters in the final part of their ascent to the surface.
Źródło:
Geological Quarterly; 2023, 67, 2; art. no. 19
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the underwater noise associated with remotely-operated vehicles
Autorzy:
Buszman, K.
Mironiuk, W.
Powiązania:
https://bibliotekanauki.pl/articles/134926.pdf
Data publikacji:
2018
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
hydroacoustic
remotely-operated vehicles
spectrum
one-third-octave
object identification
passive method
shallow water
Opis:
There is increasing demand for various types of submersible and floating remotely-operated vehicles which have herein been studied with respect to the threats posed by these kinds of objects. Local physical field disorder analyses have demonstrated the possibility of detecting and classifying objects based on hydroacoustics. Hydroaocoustic analysis results are presented as narrowband and One-Third-Octave spectra of different types of remotely-operated vehicles. Investigations were performed using an underwater measuring system located in very shallow water in a coastal zone characterized by conditions considered as poor for sound propagation.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2018, 54 (126); 129-132
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Górnośląski system informacji przestrzennej o zagrożeniach powierzchni na terenach pogórniczych
Upper Silesian system of information about surface hazards on abandoned mining areas
Autorzy:
Kotyrba, A.
Frolik, A.
Kortas, Ł.
Siwek, S.
Powiązania:
https://bibliotekanauki.pl/articles/394218.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
górnictwo
zlikwidowane kopalnie
płytka eksploatacja
zagrożenia
zapadliska
mining
abandoned mines
shallow exploitation
surface hazards
Opis:
Tereny Górnego Śląska ze względu na duże zasoby surowców mineralnych podlegały w przeszłości, i podlegają obecnie, silnej presji górniczej. Jednocześnie są to tereny, które uległy silnym procesom urbanizacji i znaczna ich część wykorzystywana jest na cele budowlane. Dokonana działalność górnicza spowodowała trwałe przeobrażenie naturalnego środowiska geologicznego. Obejmuje ono szereg cech strukturalnych oraz własności fizykochemicznych i mechanicznych utworów geologicznych a także zaburzenie w rozkładzie pola grawitacji ziemskiej. Pole to jest zasadniczą przyczyną procesów geodynamicznych kształtujących równowagę mechaniczną w litosferze. Konsekwencją przeobrażenia jest istnienie potencjalnego zagrożenia niestabilnością powierzchni terenów dokonanej eksploatacji (deformacje) a w szczególności obszarów, w których eksploatację surowców prowadzono na małej głębokości. Potencjalna niestabilność powierzchni stwarza zagrożenie bezpieczeństwa zarówno dla ludzi, jak i obiektów budowlanych. W artykule opisano projekt informatyczny realizowany w Laboratorium Geofizyki Inżynierskiej Głównego Instytutu Górnictwa mający na celu udokumentowanie dokonanej płytkiej eksploatacji górniczej węgla i rud metali na współczesnych mapach powierzchni oraz udostępnienie tej informacji w przestrzeni publicznej w postaci portalu internetowego zapadliska.gig.eu . Strona funkcjonuje na serwerze Głównego Instytutu Górnictwa pod nazwą „Górnośląski System Informacji o Zagrożeniach Powierzchni na Terenach Zlikwidowanych Kopalń”. W 2015 roku zrealizowano pierwszy etap projektu obejmujący kwerendę map górniczych północno-wschodniej części Górnośląskiego Zagłębia Węglowego, tj. Zagłębia Dąbrowskiego oraz rejonu jaworznicko-chrzanowskiego. W artykule opisano strukturę informatyczną projektu oraz wykorzystane zasoby danych kartograficznych i geologiczno-górniczych w celu jego realizacji.
Due to the large deposits of mineral resources, the Upper Silesia Area has been under strong mining pressure for the past several centuries. Nowadays, as the mines are abandoned, many post-mining regions are intended for revitalization and investments such as housing development and industrial building. The mining exploitation left transformations in the natural geological environment which have an impact on the geotechnical conditions. This includes a number of structural, physico-chemical and mechanical features of geological formations as well as disturbances in the distribution of the Earth’s gravity field. This field is the principal cause of geodynamic processes affecting the mechanical equilibrium in the lithosphere. As a consequence of mining exploitation in post mining areas surface deformations may occur, especially in places where mine extraction was conducted on a low depths. Potential surface hazards determine the safety for civil and building engineering. The main goal of the project which is developed in the Central Mining Institute is to record the areas of old shallow (up to 100 m) coal and ore exploitation on present cartographical maps. The results of the work will be presented on the website (zapadliska.gig.eu) working on the Central Mining Institute’s server. The first stage of the project focused on collecting the data from the North-East part of Upper Silesia was conducted in 2015. The structure of the project’s website and used resources of cartographical, geological and mining data has been described in the article.
Źródło:
Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN; 2016, 94; 91-103
2080-0819
Pojawia się w:
Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The occurrence and habitat requirements of Nitella syncarpa [Thuillier] Chevallier and Nitelletum syncarpae [Corillion 1957] Dambska 1996 in the Wielkopolska Region
Rozmieszczenie i warunki wystepowania Nitella syncarpa [Thuillier] Chevallier oraz Nitelletum syncarpae [Corillion 1957] Dambska 1966 w Wielkopolsce
Autorzy:
Gabka, M.
Owsianny, P.M.
Powiązania:
https://bibliotekanauki.pl/articles/878349.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu
Tematy:
habitat
locality
Polska
botany
Nitelletum syncarpae
occurrence
macrophyte
Wielkopolska region
Nitella syncarpa
shallow lake
Źródło:
Roczniki Akademii Rolniczej w Poznaniu. Botanika-Steciana; 2005, 09
1896-1908
Pojawia się w:
Roczniki Akademii Rolniczej w Poznaniu. Botanika-Steciana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of methods for nocturnal sampling of predatory zooplankters in shallow waters
Autorzy:
Linkowski, T.B.
Kornijow, R.
Kapowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/2078998.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
plankton
zooplankton
predatory species
Neomysis integer
Leptodora kindtii
Cercopagis pengoi
shallow water
Vistula Lagoon
Opis:
The aim of the study was to assess the suitability of a plankton net (diameter of 60 cm, mesh size of 500 μm) and a column sampler (length of 200 cm, diameter of 5 cm) for estimating the density of zooplankton predatory species (Neomysis integer, Leptodora kindtii, Cercopagis pengoi). Nocturnal sampling was performed once a month (May—November 2018) in the Vistula Lagoon (southern Baltic) in the range depth of 1.3—3.6 m. Statistical analysis indicated no significant differences between the N. integer and C. pengoi density estimated by the two sampling gears. In the case of L. kindtii, the mean density obtained by the column sampler was higher when analyzing all samples together and/or deep-water samples only (p < 0.02). However, no such differences were found at shallow stations i.e. up to ca. 2 m in depth. It was assumed that the more suitable sampling equipment for estimating zooplankton abundance in a shallow, well-mixed transitional (brackish) basin is the column sampler. This type of gear, so far used mainly for sampling of micro and mesozooplankton, allows the simultaneous nocturnal collection of the entire zooplankton size spectrum, including representatives of large predatory species. The suitability of light traps for qualitative studies of zooplankton species responding positively to light under the high turbidity of the Vistula Lagoon was also investigated. The traps proved to be most useful for N. integer (100% frequency), and much less for L. kindtii (46.2%) and C. pengoi (27.3%).
Źródło:
Oceanologia; 2021, 63, 1; 71-79
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tubular tempestites from Jurassic mudstones of southern Poland
Autorzy:
Leonowicz, P. M.
Powiązania:
https://bibliotekanauki.pl/articles/2059866.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
tubular tempestite
shallow-marine mudstone
omission surface
Lower Jurassic
Middle Jurassic
Silesian-Cracow region
Opis:
This paper presents tubular tempestites from southern Poland and their application for environmental and sequence stratigraphy interpretation. Tubular tempestites are present in muddy successions of the Lower Jurassic Ciechocinek Formation and in the Middle Jurassic Częstochowa Ore-Bearing Clay Formation in the Silesian-Kraków region. They occur as sand-filled tubes of Spongeliomorpha and Thalassinoides entrenched in the mudstone, which form two characteristic horizons. Tubes were emplaced in semi-consolidated substrate and filled with sand brought by storm-generated bottom currents. The trace fossils reveal features typical of Glossifungites ichnofacies associated firmgrounds, which record discontinuities in the stratigraphical record, linked with a depositional hiatus or condensation and erosion of the sea-floor. The coincidence of these horizons with early phases of regional transgressions suggests that they represent transgressive surfaces of erosion. Their limited spatial extent probably resulted from varying intensity of erosion, which locally scoured deeply down to already consolidated substrate, whereas in other places erosion was weaker or even absent, and thus it is not marked in the sedimentary record there.
Źródło:
Geological Quarterly; 2016, 60, 2; 385--394
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Full-fledged temporal processing : bridging the gap between deep linguistic processing and temporal extraction
Autorzy:
Costa, F.
Branco, A.
Powiązania:
https://bibliotekanauki.pl/articles/103861.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Podstaw Informatyki PAN
Tematy:
temporal processing
temporal extraction
tense
aspect
hybrid approaches
deep linguistic processing
shallow linguistic processing
Opis:
The full-fledged processing of temporal information presents specific challenges. These difficulties largely stem from the fact that the temporal meaning conveyed by grammatical means interacts with many extra-linguistic factors (world knowledge, causality, calendar systems, reasoning). This article proposes a novel approach to this problem, based on a hybrid strategy that explores the complementarity of the symbolic and probabilistic methods. A specialized temporal extraction system is combined with a deep linguistic processing grammar. The temporal extraction system extracts eventualities, times and dates mentioned in text, and also temporal relations between them, in line with the tasks of the recent TempEval challenges; and uses machine learning techniques to draw from different sources of information (grammatical and extra-grammatical) even if it is not explicitly known how these combine to produce the final temporal meaning being expressed. In turn, the deep computational grammar delivers richer truth-conditional meaning representations of input sentences, which include a principled representation of temporal information, on which higher level tasks, including reasoning, can be based. These deep semantic representations are extended and improved according to the output of the aforementioned temporal extraction module. The prototype implemented shows performance results that increase the quality of the temporal meaning representations and are better than the performance of each of the two components in isolation.
Źródło:
Journal of Language Modelling; 2013, 1, 1; 97-154
2299-856X
2299-8470
Pojawia się w:
Journal of Language Modelling
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Planned motion equations of free-running grain mixture flow
Autorzy:
Piven, M.
Powiązania:
https://bibliotekanauki.pl/articles/791801.pdf
Data publikacji:
2016
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
shallow water
free-running mixture
stress tensor
grain mixture
vibrating sieve
planned motion equation
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2016, 16, 4
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Analysis of Motion Dynamics and Resistance of the Multipurpose Boat Operating in Shallow Water
Autorzy:
Kulczyk, T.
Górnicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/116257.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Hydrodynamics
Motion Dynamics
Shallow Water
Miltipurpose Boat
Boat's Motion
Computer Simulation
CFD Method, Resistance
Opis:
Polish market of small boats has been developed very dynamically in recent years. Market competition forces the shipyards to build new more efficient hull forms and to cut the cost of production as well. This is why modern computer simulation programs are used more often by naval architects. Another trend is to design more universal ships that may be used by larger number of diversified customers. This paper presents project proposal of multipurpose boat hull form. The boat was design to fulfil the requirements imposed by public services like water police, fire brigades, and border guards. It is supposed to be operated on unexplored floodplains and other type shallow waters. The analysis of boat’s motion was based on computer simulations. The resistance curve was evaluated with two methods: comparison study of model test results of similar ships and CFD methods. The results obtained from Ansys Fluent and FINE/Marine systems were compared in this paper. It was shown that taking into consideration dynamic trim and sinkage has a significant impact on free surface capture and resistance values.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2014, 8, 3; 359-363
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An iterative algorithm for random upper bound kinematical analysis
Autorzy:
Chwała, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/2073758.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
random bearing capacity
shallow foundation
scale of fluctuation
iterative algorithm
upper bound
spatial variability
Opis:
A new approach for stochastic upper bound kinematical analyses is described. The study proposes an iterative algorithm that uses the Vanmarcke spatial averaging and kinematical failure mechanisms. The iterative procedure ensures the consistency between failure geometry and covariance matrix, which influences the quality of the results. The proposed algorithm can be applied to bearing capacity evaluation or slope stability problems. The iterative algorithm is used in the study to analyse the three-dimensional undrained bearing capacity of shallow foundations and the bearing capacity of the foundation for two-layered soil, in both cases, the soil strength spatial variability is included. Moreover, the obtained results are compared with those provided by the algorithm, based on the constant covariance matrix. The study shows that both approaches provide similar results for a variety of foundation shapes and scale of fluctuation values. Therefore, the simplified algorithm can be used for purposes that require high computational efficiency and for practical applications. The achieved efficiency using a constant covariance matrix for one realisation of a three-dimensional bearing capacity problem that includes the soil strength spatial variability results in about 0.5 seconds for a standard notebook. The numerical example presented in the study indicates the importance of the iterative algorithm for further development of the failure mechanism application in probabilistic analyses. Moreover, because the iterative algorithm is based on the upper bound theorem, it could be utilised as a reference for other methods for spatially variable soil.
Źródło:
Studia Geotechnica et Mechanica; 2022, 44, 1; 13--25
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of extreme flooding in a built-up area
Autorzy:
Szydłowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/241362.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
flash flooding
urban area
mathematical modelling
shallow water equations
finite volume method
numerical simulation
Opis:
Two numerical simulations of extreme (flash) flood propagation in an urban area are presented. The simulations are performed to recognize some specific features of flow in a built-up area. As the mathematical model of free surface unsteady water flow the shallow water equations are assumed. In order to solve the equations, a numerical scheme based on finite volume method is applied. For approximation of mass and momentum fluxes the Roe method is used. The calculations are examined against the experimental data. The measured variations of water depth at some control points of flooded area are available due to physical modelling. The experiments of model city flooding events were carried out at the hydraulic laboratory of ENEL-CESI in Milan (Italy) in a framework of EC IMPACT project. The aim of these experiments was to simulate a flood in the area where a building group representing a simplified city configuration was introduced.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 4; 321-333
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronization system for underwater acoustic communications using in shallow waters
Autorzy:
Schmidt, Jan H.
Schmidt, Aleksander M.
Powiązania:
https://bibliotekanauki.pl/articles/24201990.pdf
Data publikacji:
2023
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
synchronization system
underwater acoustic communications
shallow water
układy synchronizacji
akustyczna komunikacja podwodna
wody płytkie
Opis:
A reliable synchronization system of the transmitted data frame has a significant impact on the efficiency of the underwater communication system. This applies in particular to communication systems dedicated to work in shallow waters, where the phenomenon of multipath permanently occurs. To overcome these difficulties, the concept of a synchronization system consisting of two broadband signals of opposite monotonicity was presented. The method of receiving these signals has been described in detail. The stochastic channel model with Rician fading and the Watermark simulator was used to test the efficiency of the synchronization system in the underwater multipath channel.
Źródło:
Vibrations in Physical Systems; 2023, 34, 1; art. no. 2023102
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave-induced set-up and flow over shoals and coral reefs. Part 1. A simplified bottom geometry case
Autorzy:
Massel, S.R.
Brinkman, R.M.
Powiązania:
https://bibliotekanauki.pl/articles/47564.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
shoal
hydrodynamics
coral reef
shallow
biological variability
wave motion
morphology
water depth
linear function
Opis:
An analytical approach was used to model the wave-induced set-up and flow through simple shoal geometry when water depth is a linear function of the distance. Two different approaches were applied to parameterize the energy dissipation due to wave breaking. The resulting set-up height and flow velocity were determined and their dependence on the geometry of the shoal and offshore forcing was demonstrated. The extension of the solution to a more complicated bathymetry and verification against the experimental data will be given in the second part of the paper.
Źródło:
Oceanologia; 2001, 43, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Balance errors in numerical solutions of shallow water equations
Autorzy:
Gąsiorowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/1933150.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska
Tematy:
shallow water equations
nonlinear advection equations
numerical errors
conservation laws
mass and momentum balance
Opis:
An analysis of the conservative properties of shallow water equations is presented, focused on the consistency of their numerical solution with the conservation laws of mass and momentum. Two different conservative forms are considered, solved by an implicit box scheme. Theoretical analysis supported with numerical experiments is carried out for a rectangular channel and arbitrarily assumed flow conditions. The improper conservative form of the dynamic equation is shown not to guarantee a correct solution with respect to the conservation of momentum. Consequently, momentum balance errors occur in the numerical solution. These errors occur when artificial diffusion is simultaneously generated by a numerical algorithm.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 4; 329-340
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of shallow mine-workings on crack failure of overburden strata
Wpływ płytkich wyrobisk kopalnianych na spękania warstw nadkładu
Autorzy:
Xueyi, Y.
Senlin, H.
Powiązania:
https://bibliotekanauki.pl/articles/350148.pdf
Data publikacji:
2005
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
płytkie wyrobisko
szkody górnicze
metoda kontrolowanej eksploatacji górniczej
shallow seam
mining damage
controlled mining
Opis:
Coal exploitation in Shendong mining area in Shaanxi province of China is based on shallow mine-workings, which is the main reason for surface subsidence. A great deal of analysis and research indicates that the crack damage is controlled by the key stratum in the overburden strata. The paper studies the relationship between the stability condition of the key stratum structure and the mining damage, supplying the theoretical evidence for implementing an effective mining method to protect the environment in Shendong mining area.
Eksploatacja złóż węgla kamiennego w okręgu górniczym Shendong w chińskiej prowincji Shaanxi prowadzona jest na małych głębokościach. Powoduje to szereg problemów związanych z ochroną środowiska naturalnego, które są rozwiązywane w celu dalszego rozwoju zagłębia. Główną przeszkodę w wydobyciu węgla stanowią deformacje występujące w warstwach nadkładu oraz osiadania powierzchni terenu. Następstwem deformacji jest niszczenie roślinności na powierzchni, znaczące pogorszenie się stanu środowiska naturalnego oraz nieuchronne przekształcanie się żyznych terenów rolniczych w tereny o charakterze pustynnym. W warunkach gdy nad prowadzoną eksploatacją występują grube warstwy gruntów piaszczystych pochodzenia eolicznego oraz warstwy skalne o małej miąższości, szkody górnicze objawiają się bardzo intensywnie. Autorzy artykułu przeprowadzili pionierskie badania w zakresie wpływu eksploatacji górniczej na deformacje nieciągłe górotworu. Zakładając, że pojawienie się spękań w głównej mierze uzależnione jest od tzw. warstwy kluczowej w nadkładzie, zbadano zależność między warunkami określającymi stateczność tejże warstwy a powstałymi szkodami górniczymi. Autorzy artykułu dokonują powyższej analizy, stosując między innymi metody numeryczne. Otrzymane wyniki badań i obliczeń mogą dać podstawy do doboru skutecznej metody eksploatacji, która może być zastosowana w celu zapewnienia właściwej ochrony środowiska naturalnego w zagłębiu Shendong.
Źródło:
Górnictwo i Geoinżynieria; 2005, 29, 3/1; 511-519
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Cretaceous palaeogeography of NE Bohemian Massif : diachronous sedimentary successions in the Wleń Graben and Krzeszów Brachysyncline (SW Poland)
Autorzy:
Kowalski, Aleksander
Powiązania:
https://bibliotekanauki.pl/articles/1836017.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Sudetic epi-Variscan cover
shallow-marine palaeostrait
wave-dominated sedimentation
tidal currents
offshore transition
Opis:
This paper provides a new sedimentological and palaeogeographic interpretation of the Late Cretaceous (late Cenomanian to early Coniacian) shallow-marine succession exposed in the Wleń Graben and in the Krzeszów Brachysyncline (NE Bohemian Massif, Sudetic Block). These two tectonic subunits are outliers of the North Sudetic and Intra-Sudetic synclinoriums, respectively, and contain relics of the diachronous sedimentary succession of a seaway linking the Boreal and Tethyan marine provinces during the Late Cretaceous. Results of sedimentological study and facies analysis show that the late Cenomanian sedimentation within this corridor was dominated by strong in situ reworking of the pre-Cretaceous bedrock driven by storm waves and possibly tidal currents. In the latest Cenomanian, siliciclastic sedimentation was followed by the deposition of offshore-transition to offshore muddy calcareous facies in the Krzeszów area, while the deposition of coarse-grained siliciclastic facies continued in the Wleń area. The nearshore clastic belt in the latter area changed into a wider strait dominated by offshore sedimentation in the early Turonian, whereby the interconnected Wleń and Krzeszów passages evolved into a uniform strait of fully-marine sedimentation. In the middle Turonian, the southern part of the strait became progressively filled with coarse-grained siliciclastic material supplied from the east. At the end of the late Turonian and in the early Coniacian, the strait funnelled bi-directional tidal currents along its axis. The youngest Cretaceous strata in the Wleń area comprise erosional relics of the early Coniacian shoreface to offshore-transition deposits. The younger Cretaceous deposits are unpreserved, probably eroded during the post-Santonian(?) tectonic inversion of the Wleń–Krzeszów strait. Despite the relatively small distance between the two relic parts of the strait, the shallow-marine succession reveals distinct diachroneity on a regional scale, reflecting an interplay of eustatic changes, differential tectonic subsidence and clastic sediment supply. This paper presents the first detailed sedimentological logs from the two study areas, with new findings of fossil fauna and flora, proposes a new palaeogeographic interpretation and discusses the influence and development of the source areas for the Cretaceous Sudetic Wleń–Krzeszów marine strait at the NE fringe of the Bohemian Massif.
Źródło:
Annales Societatis Geologorum Poloniae; 2021, 91, 1; 1-26
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Matched-field Source Localization with a Mobile Short Horizontal Linear Array in Offshore Shallow Water
Autorzy:
Zhao, D.
Huang, Z.
Su, S.
Li, T.
Powiązania:
https://bibliotekanauki.pl/articles/177986.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
passive source localization
matched-field processing
inter-position processing
short horizontal array
shallow water
Opis:
Passive source localization in shallow water has always been an important and challenging problem. Implementing scientific research, surveying, and monitoring using a short, less than ten meter long, horizontal linear array has received considerable attention in the recent years. The short array can be conveniently placed on autonomous underwater vehicles and deployed for adaptive spatial sampling. However, it is usually difficult to obtain a sufficient spatial gain for localizing long-range sources due to its limited physical size. To address this problem, a localization approach is proposed which is based on matched-field processing of the likelihood of the passive source localization in shallow water, as well as inter-position processing for the improved localization performance and the enhanced stability of the estimation process. The ability of the proposed approach is examined through the two-dimensional synthetic test cases which involves ocean environmental mismatch and position errors of the short array. The presented results illustrate the localization performance for various source locations at different signal- to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the short array moves at a low speed along a straight line at a certain depth.
Źródło:
Archives of Acoustics; 2013, 38, 1; 105-113
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the WetSpass simulation model for determining conditions governing the recharge of shallow groundwater in the Poznań Upland, Poland
Autorzy:
Graf, R.
Przybyłek, J.
Powiązania:
https://bibliotekanauki.pl/articles/94262.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
shallow groundwater recharge
water balance
lowland catchment
płytkie wody gruntowe
bilans wodny
zlewnia nizinna
Opis:
Assessments of the infiltration recharge of groundwater are performed using various methods and on different scales. Infiltration is dependent of climatic factors, aspects of water circulation, as well as on quasi-stationary and variable environmental features of a specific area, which are frequently difficult to determine on the basis of direct measurements or observations. The objective of the present study was to identify factors conditioning recharge of shallow groundwater in selected catchment areas of the Poznań Upland using the WetSpass simulation water balance model with spatially distributed parameters. Our analysis has indicated favourable and unfavourable conditions for recharge of groundwater in the annual period and in both half-year periods, which are the result of mutual relationships between the physical qualities of these catchment areas and their climatic and hydrological characteristics. The results obtained also confirmed the impact of surface runoff and actual evapotranspiration on the spatial distribution of effective infiltration. With soil types and groundwater depth distributions being similar in the catchment areas, changes in relationships between components of water balance are caused by differences in the type of land usage. Application of the WetSpass model has made it possible to arrive at a more accurate assessment of groundwater recharge. The results obtained may be used for erification of recharge areas and values of effective infiltration, set as a boundary condition in groundwater flow models.
Źródło:
Geologos; 2018, 24, 3; 189-205
1426-8981
2080-6574
Pojawia się w:
Geologos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Facies characterisation of a shallow-water deltaic succession: the Upper Jurassic Wagad Sandstone Formation of Kachchh, western India
Autorzy:
Joseph, J. K.
Patel, S. J.
Powiązania:
https://bibliotekanauki.pl/articles/94430.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Lithofacies
Oxfordian/Kimmeridgian
offshore
shallow-water delta
South Wagad Fault
litofacja
oksford
kimeryd
delta
Opis:
Ancient deltaic facies are difficult to differentiate from tidally influenced shallow-marine facies. The Wagad Sandstone Formation of the Wagad Highland (eastern Kachchh Basin) is typified by offshore and deltaic facies with sedimentary characteristics that represent different conditions of hydrodynamics and related depositional processes. The study area, the Adhoi Anticline, constitutes a ~154-m-thick, shale-dominated sequence with progressive upward intercalations of bioturbated micritic sandstone and quartz arenite. Two thick Astarte beds (sandy allochemic limestone), with an erosional base and gravel blanketing, illustrate tidal amplification and high-energy stochastic events such as storms. Sedimentological characteristics document three depositional facies: an offshore, shale-dominated sequence prograding to proximal prodeltaic micritic sandstone and quartz arenite with sandy allochemic limestones, further prograding to mouth bars and abandoned channel deposits. The Wagad Sandstone Formation displays depositional environmental conditions that are dissimilar from those of coeval deposits in Kachchh sub-basins as well as on regional and global scales. This is attributed to a reactivation of the Kachchh Mainland and South Wagad faults which resulted in detachment and uplift of the Wagad block which then experienced prograding deltaic conditions.
Źródło:
Geologos; 2018, 24, 2; 137-150
1426-8981
2080-6574
Pojawia się w:
Geologos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of sinkhole hazard in the post-mining area using the ERT method and numerical modeling
Autorzy:
Ścigała, Roman
Szafulera, Katarzyna
Jendryś, Marek
Powiązania:
https://bibliotekanauki.pl/articles/29521070.pdf
Data publikacji:
2023
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
shallow excavations
sinkhole threat
ERT method
numerical modeling
finite difference method
protection of mining areas
Opis:
The loss of stability of shallow voids existing in the rock mass often results in the formation of sinkholes on the surface. This has a significant impact on the threat to public safety. Therefore, it is crucial to recognize the presence of such voids, especially in old post-mining areas, where shallow extraction was previously conducted, and there is a lack of mapping documentation indicating the location of underground workings. This paper presents an example illustrating a proposed procedure for recognizing shallow voids, which consists of two research works: geophysical research combined with numerical analyzes used as a kind of forward modeling. This combination increases the possibility of accurately locating potential sinkhole occurrences. The first part of this article provides selected literature information on the occurrence of sinkhole hazards. The second part presents the results of subsurface layer investigations of the rock mass conducted using electrical resistivity tomography (ERT). The third part focuses on assessing the threat of sinkhole formation by using forward numerical modeling performed with the FLAC 3D software to confirm the subsurface structures identified through the ERT method. The results of the analyzes conducted with both methods are then discussed in terms of their suitability for assessing the associated risk. The research conducted within the framework of this study confirms the effectiveness of the ERT method combined with numerical modeling for evaluating the state of the rock mass. This method can be considered a valuable tool for supporting decision-making in identifying post-mining areas that are particularly at risk of sinkhole formation.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2023, 75 (147); 20-34
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Attenuation of wave-induced groundwater pressure in shallow water. Part 1
Autorzy:
Massel, S.R.
Przyborska, A.
Przyborski, M.
Powiązania:
https://bibliotekanauki.pl/articles/49074.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
fluctuation
oceanic water
attenuation
filtration
groundwater pressure
sandy beach
beach ecosystem
surface wave
shallow water
Opis:
A coastal aquifer has a dynamic seaward boundary at the beach face where physical and ecological processes are influenced by oceanic water level fluctuations. Many basic groundwater concepts and the role of the impact of groundwater seepage on beach ecosystems are still poorly understood. Studies are needed to improve our understanding of the relationships between surface and subsurface flow processes on beaches. This is particularly helpful in clarifying the interaction of the physical processes, biodiversity and productivity of sandy beaches, sediment transport and coastal structure stability and modern beach nourishment techniques. As the estimation of infiltration into beach sand is very difficult to carry out under real sea conditions, a control led large-scale laboratory experiment was carried out in the LargeWave Channel in Hannover (Germany) as part of a project supported by the European Community (contract HPRI-CT-2001-00157). First part of the paper describes the technology applied in the experiment and reports some preliminary results.
Źródło:
Oceanologia; 2004, 46, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zawartość trytu i skład izotopowy tlenu w płytkich wodach podziemnych w punktach badawczych krajowej sieci monitoringu
Tritium content and oxygen isotopic composition in shallow groundwater in observation points of the national monitoring network
Autorzy:
Nowicki, Z.
Leśniak, P.M.
Wilamowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2075445.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
tryt
stabilne izotopy
czas przebywania
płytkie wody podziemne
tritium
stable isotopes
residence time
shallow groundwater
Opis:
The points of the national network of groundwater monitoring comprise a stable benchmarks in quality and quantity monitoring. The obtained data (tritium and δ18O) are important for understanding the groundwater cycling and are indirect indicators of aquifer vulnerability to anthropogenic pollution. The goal of this paper is to present the relation of the tritium content and delta value of stable isotopes of oxygen against the groundwater sampling depth in 2004–2012. It is demonstrated that the remains of “nuclear” tritium concentration is still present in groundwater as a tritium peak at depths around 30 m. Determination of dynamics of recharge in groundwater bodies, based on national network observation points is associated to the estimation of the groundwater residence time in aquifers and remains one the vital problem of hydrogeology.
Źródło:
Przegląd Geologiczny; 2015, 63, 10/2; 976--980
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution of the dike-break problem using finite volume method and splitting technique
Autorzy:
Gąsiorowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/1934027.pdf
Data publikacji:
2011
Wydawca:
Politechnika Gdańska
Tematy:
finite volume method
shallow water equations
approximate Riemann solver
dambreak
dike-break
wave-propagation method
Opis:
In this paper, an approach using the finite volume method (FVM) for the solution of two-dimensional shallow water equations is described. Such equations are frequently used to simulate dam-break and dike-break induced flows. The applied numerical algorithm of the FVM is based on a wave-propagation algorithm, which ensures a stable solution and, simultaneously, minimizes numerical errors. Dimensional decomposition according to the coordinate directions was used to split two-dimensional shallow water equations into one-dimensional equations. Additionally, splitting was also applied with respect to the physical processes. The applied dimensional and physical splitting, together with the wave-propagation algorithm led to an effective algorithm and ensured proper incorporation of source terms into the scheme of the finite volume method. A detailed description of an approximation for numerical fluxes and source terms is presented. The obtained numerical results are compared with analytical solutions, laboratory experiments and other results available in the literature.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2011, 15, 3-4; 251-270
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Overlying sand-inrushing mechanism and associated control technology for longwall mining in shallow buried coal seams with the soft surrounding rock
Autorzy:
Wang, Fangtian
Shao, Dongliang
Zhang, Cun
Zhang, Chenkai
Song, Ziyu
Powiązania:
https://bibliotekanauki.pl/articles/2203348.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
górnictwo
węgiel
skała
shallow-buried coal
soft rock
sand inrushing
cracks
safe and efficient
mining
Opis:
Taking the sand-inrushing accident of the Selian No. 1 coal mine in the Ordos of inner Mongolia as the research background, four main factors of sand-inrushing, including sand source, channel, sand-breaking power, and flowing space, were analysed. The disaster formation process (SCPS) illustrated that sand-inrushing disasters in shallowly buried coal seams with soft surrounding rock have the characteristics of being significantly influenced by mining, the development of vertical overburden channels, and sufficient space for water-sand mixed particles to flow. Universal Distinct Element Code (UDEC) software has been used to reveal that the vertical cracks in the overburden between the coal wall and support undergo a process of development and expansion along with the cumulative stress of mining. This showed that the vertical fissure through the overburden is the main pathway for the disaster. Combined with the site conditions, disaster occurrence mechanism, and numerical simulation results, a comprehensive prevention and control technology based on the working face and roadway grouting to block the channel was proposed. It contains reasonable mining height and optimisation of advancing speed, so that safe and efficient mining of coal seams in shallow-buried soft surrounding rocks could be achieved.
Źródło:
Archives of Mining Sciences; 2022, 67, 4; 681--697
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potas w glebie, roślinności i płytkich wodach gruntowych na tle zróżnicowanego użytkowania
Potassium in soil, Plants and ahallow ground waters in relation to different meadow utilisation
Autorzy:
Burzyńska, I.
Powiązania:
https://bibliotekanauki.pl/articles/338168.pdf
Data publikacji:
2012
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
gleba mineralna
potas
płytkie wody gruntowe
roślinność łąkowa
mineral soil
potassium
shallow ground waters
meadow vegetation
Opis:
Celem pracy była ocena wpływu zróżnicowanego użytkowania łąki na glebie mineralnej na zawartość potasu w glebie, roślinności łąkowej oraz w płytkich wodach gruntowych. Badania prowadzono na długoletnim doświadczeniu łąkowym założonym w 1981 r. na czarnej ziemi zdegradowanej w Laszczkach, w województwie mazowieckim. W latach 2001-2010 pobierano próbki gleby i płytkich wód gruntowych. Natomiast próbki roślinności łąkowej pobierano w czasie I pokosu w latach 2009-2010. W wyciągu glebowym 0,01 mol CaCl2·dm-³ w wodach gruntowych oraz w roztworach mineralizowanych próbek roślinności łąkowej oznaczono zawartość K metodą płomieniowej spektrometrii atomowej (FAAS). Długotrwałe nawożenie saletrą wapniową stabilizowało odczyn gleby oraz przeciwdziałało stratom łatwo rozpuszczalnego K z gleby łąkowej. Koszenie i usuwanie roślinności z powierzchni poletek przyczyniło się do zmniejszenia zawartości K w glebie, szczególnie w warunkach odczynu umiarkowanie kwaśnego. Stężenie potasu w płytkich wodach gruntowych było uzależnione od sposobu użytkowania łąki. Zaniechanie produkcyjnego użytkowania łąki przyczyniło się do znacznych sezonowych wahań stężenia K w płytkich wodach gruntowych.
The aim of this study was to assess the effect of diversified use of a meadow on potassium content in the soil, meadow vegetation and in shallow ground waters. The studies were carried out in a long-term grassland experiment initiated in 1981 in Laszczki in the Masovian Province. Samples of soil and shallow ground water from control wells were collected in 2001-2010. Plant samples were taken during the first cut in the years 2009-2010. Potassium content was measured with the flame atomic absorption spectrophotometry in 0.01 mol CaCl2·dm-³ soil extracts, in ground waters and in the samples of meadow vegetation after their mineralisation. Long-term fertilisation with calcium nitrate stabilized soil pH and counteracted the losses of easily soluble K from meadow soil. Mowing and removal of meadow vegetation from the surface of plots reduced K content in the soil, especially under moderately acidic soil pH. Potassium concentration in shallow ground water depended on the way the meadow was used. The abandonment of productive use of the meadow contributed to substantial seasonal variations of K concentration in shallow ground waters.
Źródło:
Woda-Środowisko-Obszary Wiejskie; 2012, 12, 1; 49-58
1642-8145
Pojawia się w:
Woda-Środowisko-Obszary Wiejskie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimisation of Shallow Water Coefficients Based on Sea Trials Manoeuvring
Identyfikacja parametrów efektu płytkowodzia na podstawie prób morskich
Autorzy:
Artyszuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/360181.pdf
Data publikacji:
2004
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
manewrowanie
model matematyczny
płytkowodzie
identyfikacja
EXPLO-SHIP 2004
manoeuvring
mathematical model
shallow water
identification
full-scale
Opis:
Restricted water effects upon ship manoeuvring are investigated from the full-scale based identification viewpoint. As the resistance increase may be quite accurately correlated with the squat, it is proposed to store in the ship manoeuvring model kernel only data on the ship's squat. The problem of correction factors (multipliers) to be imposed upon ship added masses and hull force coefficients is raised. Different patterns (combinations) of the multipliers are simulated to show the most representative ship behaviour with regard to turning and zigzag manoeuvres.
Przeanalizowano wpływ ograniczeń hydraulicznych akwenu na manewrowanie statkiem w aspekcie identyfikacji hydrodynamicznego modelu ruchu z prób morskich. W odniesieniu do modelowania wzrostu oporów zaleca się ich uzależnienie od aktualnego osiadania. Przeprowadzono symulację różnych konfiguracji współczynników korekcyjnych hydrodynamiki kadłuba na warunki płytkowodzia celem otrzymania charakterystycznych zachowań statku w próbach cyrkulacji i wężowej.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2004, 2 (74); 33-43
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new Triassic-Jurassic section in the southern part of the Holy Cross Mts. (Poland) implications for palaeogeography
Autorzy:
Kozłowska, M.
Barski, M.
Mieszkowski, R.
Antoszewska, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059877.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
sedimentology
fluvial deposits
shallow marine deposits
Middle Jurassic transgression
dinoflagellate cysts
stratigraphy
electrical resistivity tomography
ERT
Opis:
Sedimentological, stratigraphical and geophysical studies across a new Triassic-Jurassic transition section in the Holy Cross Mts., Poland have revealed a large sedimentary hiatus embracing the entire latest Triassic–Early Jurassic – earliest Middle Jurassic time interval and yielded new data on the Triassic fluvial system and on Middle Jurassic shallow marine sedimentation. The presence of organic-walled dinoflagellate cysts allowed a precise age assignment of the black clay facies. Regional discussions and comparisons may be made with other areas with a similar depositional environment in Poland. For the first time a counterpart of the “Kościeliskie Beds” lithostratigraphic unit is proposed to exist in the Holy Cross Mts. area.
Źródło:
Geological Quarterly; 2016, 60, 2; 365--484
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane aspekty dotyczące posadowień budynków
Selected aspects of buildings foundations
Autorzy:
Hulboj, R.
Major, M.
Powiązania:
https://bibliotekanauki.pl/articles/2068298.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska
Tematy:
dom jednorodzinny
fundament
posadowienie budynku
posadowienie bezpośrednie
fundament bezpośredni
detached house
foundation
building foundation
shallow foundation
Opis:
W artykule podkreślono wybrane aspekty dotyczące posadowienia budynków na przykładzie współcześnie realizowanych domów jednorodzinnych. Omówiono podstawowe typy fundamentów bezpośrednich i wskazano na dobór rozwiązań uzależnionych nie tylko od parametrów gruntu, ale również od rodzaju technologii budowy domu jednorodzinnego.
This paper presents selected aspects of buildings foundations on the example of contemporary implemented houses. There were discussed the main types of direct foundations and it was pointed to the selection of solutions which depend not only on soil parameters but also on the type of technology used to build a detached house.
Źródło:
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo; 2014, 20 (170); 81--88
0860-7214
Pojawia się w:
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Groundwater flow due to a nonlinear wave set-up on a permeable beach
Autorzy:
Przyborska, A.
Powiązania:
https://bibliotekanauki.pl/articles/47606.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
pore pressure
groundwater circulation
nonlinear wave
water flow
beach sand
shallow water
wave dynamics
coastal zone
Źródło:
Oceanologia; 2014, 56, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of climate change on the Curonian Lagoon water balance components, salinity and water temperature in the 21st century
Autorzy:
Jakimavicius, D.
Kriauciuniene, J.
Sarauskiene, D.
Powiązania:
https://bibliotekanauki.pl/articles/47688.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
climate change
Curonian Lagoon
shallow water
water balance
water temperature
water salinity
coastal environment
meteorological parameter
Źródło:
Oceanologia; 2018, 60, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena przydatności terenów pogórniczych do celów budowlanych w rejonach dawnej płytkiej eksploatacji górniczej
Evaluation of mining areas for construction regions of old shallow mining operation
Autorzy:
Mzyk, T.
Gorol, M.
Powiązania:
https://bibliotekanauki.pl/articles/112822.pdf
Data publikacji:
2017
Wydawca:
STE GROUP
Tematy:
zagospodarowanie przestrzenne
płytkie zroby
warunki posadowienia obiektu budowlanego
planning
shallow excavations
conditions of a building foundation
Opis:
W artykule przedstawiono problematykę oceny warunków geologiczno-górniczych terenów zlikwidowanych kopalń. Wykazano konieczność zaangażowania projektanta budowlanego i inwestora w identyfikację i rozpoznanie zagrożeń wynikających z możliwości powstania deformacji, w szczególności wskutek występowania płytkich zrobów górniczych. Przedstawiono problem rozproszenia materiałów i informacji źródłowych w licznych instytucjach. Problematykę oceny przydatności terenu do zabudowy przedstawiono na wybranym przykładzie.
The article presents the problem of assessment of geological-mining areas of closed mines. It has been demonstrated the need to involve a designer and building investor in the identification and recognition of the risks of deformations in particular with localized shallow excavations. Presents the problem of scattering materials and basic information. The issue of assessing the suitability of land for building shown in the example chosen.
Źródło:
Systemy Wspomagania w Inżynierii Produkcji; 2017, 6, 3; 160-170
2391-9361
Pojawia się w:
Systemy Wspomagania w Inżynierii Produkcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seasonal changes of nutrients concentration in two shallow estuarine lakes gardno and Lebsko; Comparison
Sezonowe zmiany stężenia składników biogenicznych dwóch płytkich jezior przymorskich Gardna i Łebska; Porównanie
Autorzy:
Jarosiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/85087.pdf
Data publikacji:
2009
Wydawca:
Akademia Pomorska w Słupsku
Tematy:
seasonal change
nutrient concentration
shallow lake
Lake Gardno
Lake Lebsko
comparison
phosphorus
nitrogen
eutrophication
aquatic ecosystem
Opis:
The aim of this paper was the presentation and comparison of seasonal biogens changes and trophy state classification of two biggest shallow coastal lakes Gardno and Łebsko, located in the northern part of Poland, along the southern coast of the Baltic Sea. Measurements were conducted once a month from April to December 2007. For the purpose of this article at each lake one measurement station was selected, to represent well mixed area of the lakes, far from outlet to the sea and rivers. Performed measurements showed that the lakes are similar. The differences, observed between biogens concentration in lakes were statistically insignificant. Seasonal dynamics of nutrients concentration in lakes indicated that the lakes are typical shallow lakes. Moreover, the summer concentration of total nitrogen and phosphorus qualify these lakes as eutrophic.
Celem niniejszego opracowania była prezentacja i porównanie sezonowych zmian stężenia substancji biogenicznych oraz określenie poziomu trofii dwóch jezior przymorskich Gardna i Łebska. Jeziora te zlokalizowane są wzdłuż południowego wybrzeża Morza Bałtyckiego. Zaprezentowane rezultaty są wynikiem badań prowadzonych od kwietnia do grudnia 2007 roku. Do celów publikacji na każdym z jezior wyselekcjonowane zostało jedno stanowisko pomiarowe, charakteryzujące się zarówno minimalnym oddziaływaniem słonych wód morskich, jak i słodkich wód rzecznych. Przeprowadzone analizy wykazały, iż dynamika składników biogenicznych w omawianych jeziorach jest podobna, a różnice stężenia poszczególnych form azotu i fosforu nie są istotne statystycznie. Ponadto zaobserwowano, że sezonowe zmiany stężenia biogenów w Gardnie i Łebsku mają przebieg typowy dla jezior płytkich. Określenie poziomu trofii jezior opierało się na porównaniu letnich stężeń azotu i fosforu całkowitego w toni wodnej jezior. Na podstawie tych porównań zarówno Łebsko, jak i Gardno zakwalifikowano do typu eutroficznego.
Źródło:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline; 2009, 13 part I
1643-0115
Pojawia się w:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction capabilities of the LSTM and Perceptron models based on the Day-Ahead Market on the Polish Power Exchange S.A.
Autorzy:
Ruciński, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/27323577.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Tematy:
shallow networks
deep networks
Day-Ahead Market
MATLAB
Simulink environment
neural modeling
prediction time
electricity prices
Opis:
The main purpose of the research was to examine the properties of models for two kinds of neural networks, a deep learning models in which the Long Short-Term Memory was chosen and shallow neural model in which the Perceptron Neural Network was chosen. The subject of the examination was the Day-Ahead Market system of PPE S.A. The article presents the learning results of both networks and the results of the predictive abilities of the models. The research was conducted based on data published on the Polish Stock Exchange for the 2018 year. The MATLAB environment was chosen as a tool for providing the examinations. The determination index (R2) and the mean square error (MSE) was adopted as the network evaluation criterion for the learning ability and for the prediction ability of both networks.
Źródło:
Studia Informatica : systems and information technology; 2023, 1(28); 69--82
1731-2264
Pojawia się w:
Studia Informatica : systems and information technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short-term and seasonal variability of mesozooplankton at two coastal stations (Gdynia, Sopot) in the shallow water zone of the Gulf of Gdańsk
Autorzy:
Jozefczuk, A.
Guzera, E.
Bielecka, L.
Powiązania:
https://bibliotekanauki.pl/articles/48833.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
zooplankton
Sopot
mesozooplankton
Gdynia
coastal station
seasonal variation
short-term variability
Gdansk Gulf
shallow water zone
Opis:
The idea of the study was to describe short-term and seasonal variations in the composition and abundance of zooplankton in the coastal area of the Gulf of Gdańsk at two shore stations and the influence of selected environmental factors (temperature, salinity, wind velocity) on it. The studies were based on material collected in the shallow waters of the Gulf of Gdańsk from stations located by the Marine Promenade (Bulwar Nadmorski) in Gdynia and the pier in Sopot. Samples were collected in 2001 mainly at weekly intervals using an open-type plankton net. Environmental parameters were measured at the same time. The zooplankton at the Gdynia and Sopot stations consisted of 30 taxa; Rotatoria, Copepoda and meroplankton were dominants. There was a much higher percentage of Rotatoria and a lower percentage of meroplankton at Sopot than at Gdynia. Considerable differences were apparent in the numbers of particular groups of zooplankton at these stations in the same periods. Simpson’s biodiversity index, here based on the zooplankton of the shallow waters off Gdynia and Sopot, was relatively high most of the time. Diversity of mesozooplankton was greatest in July and October. There was a significant correlation between the abundance of mesozooplankton and environmental factors in the case of cladoceran and polychaete larvae. Frequent studies at stations located close to each other illustrate the highly dynamic range of variations occurring in the coastal area: the concentrations of particular organisms fluctuated very considerably from one week to another, even by a factor of several dozen. Nevertheless, the statistically mean numbers of zooplankton at both stations are comparable.
Źródło:
Oceanologia; 2003, 45, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Challenges in scaling of CMOS devices towards 65 nm node
Autorzy:
Jurczak, M.
Veloso, A.
Rooyackers, R.
Augendre, E.
Mertens, S.
Rotschild, A.
Scaekers, M.
Lindsay, R.
Lauwers, A.
Henson, K.
Severi, S.
Pollentier, I.
Keersgieter de, A.
Powiązania:
https://bibliotekanauki.pl/articles/308984.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
CMOS devices
gate dielectrics
shallow junctions
silicide
gate stack
lithography
gate patterning
silicon recess
device integration
Opis:
The current trend in scaling transistor gate length below 60 nm is posing great challenges both related to process technology and circuit/system design. From the process technology point of view it is becoming increasingly difficult to continue scaling in traditional way due to fundamental limitations like resolution, quantum effects or random fluctuations. In turn, this has an important impact on electrical device specifications especially leakage current and the circuit power dissipation.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 1; 3-6
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A finite element method for extended KdV equations
Autorzy:
Karczewska, A.
Rozmej, P.
Szczeciński, M.
Boguniewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/330630.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
shallow water wave problem
nonlinear equations
second order KdV equations
finite element method
Petrov–Galerkin method
Opis:
The finite element method (FEM) is applied to obtain numerical solutions to a recently derived nonlinear equation for the shallow water wave problem. A weak formulation and the Petrov–Galerkin method are used. It is shown that the FEM gives a reasonable description of the wave dynamics of soliton waves governed by extended KdV equations. Some new results for several cases of bottom shapes are presented. The numerical scheme presented here is suitable for taking into account stochastic effects, which will be discussed in a subsequent paper.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 3; 555-567
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance of coherent modulation scheme used in acoustic underwater communication system
Autorzy:
Schmidt, Jan H.
Schmidt, Aleksander M.
Kochańska, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/127757.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
underwater acoustic communications
shallow underwater channel
coherent modulation
akustyczna komunikacja podwodna
płytki kanał podwodny
modulacja koherentna
Opis:
The development of an acoustic underwater communication system for shallow waters is still a big scientific and construction challenge. Currently, non-coherent modulations in combination with strong channel coding are used to achieve reliable communication with low rate in such a channel. To obtain transmission with a higher transmission rate, it is required to use coherent modulation. This paper presents the assumptions of such a transmission system and the results of data transmission carried out by this system in the channel with the Rician fading, which reflects the short range shallow water channel. A digital version of the carrier phase modulation known as Phase-Shift Keying was selected for simulation.
Źródło:
Vibrations in Physical Systems; 2019, 30, 1; 1-8
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fotografia żywi się różnicami
When photography feeds on differences
Autorzy:
Drozdowski, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/2157571.pdf
Data publikacji:
2022-07-31
Wydawca:
Narodowe Centrum Kultury
Tematy:
kryzys fotografii
orientacje na różnice
dezintegracja
płytkie wspólnoty
crisis of photography
orientation to differences
disintegration
shallow communities
Opis:
The aim of this article is to conduct a critical analysis of the human-bonding and community-building functions of photography. While photography has contributed to social integration in many ways, it is also partially responsible for the shrinking of the intersubjective community based on shared social values and meanings. More often than on similarities photography is increasingly focusing on differences, deviations, and exceptions. This is what it is mostly valued for and considered worthy of interest. However, knowing that photography can also lead to social disintegration, some people are beginning to approach it with a growing distrust and try to marginalise it, both symbolically and functionally. Between these two extremes there emerges another position. It includes using photography to build weak and shallow communities that are not particularly demanding of their members. While they support general integration, the downside is that this process is largely concentrated on secondary or even tertiary issues.
Źródło:
Kultura Współczesna. Teoria. Interpretacje. Praktyka; 2022, 118, 2; 95-103
1230-4808
Pojawia się w:
Kultura Współczesna. Teoria. Interpretacje. Praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
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