Wyniki wyszukiwania - Biblioteka Nauki

1

Air quality modeling in Warsaw Metropolitan Area

100%

Holnicki P. , Nahorski Z.

Journal of Theoretical and Applied Computer Science

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2013

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tom Vol. 7, nr 1

56--69

EN

Decision support of air quality management needs to connect several categories of the input data with the analytical process of air pollution dispersion. The aim of the respective model of air pollution is to provide a quantitative assessment of environmental impact of emission sources in a form of spatial/temporal maps of pollutants’ concentration or deposition in the domain. These results are in turn used in assessment of environmental risk and supporting respective planning actions. However, due to the complexity of the forecasting system and the required input data, such environmental prognosis and related decisions contain many potential sources of imprecision and uncertainty. The main sources of uncertainty are commonly considered meteorological and emission input data. This paper addresses the problem of emission uncertainty, and impact of this uncertainty on the forecasted air pollution concentrations and adverse health effects. The computational experiment implemented for Warsaw Metropolitan Area, Poland, encompasses one-year forecast with the year 2005 meteorological dataset. The annual mean concentrations of the main urban pollutants are computed. The impact of uncertainty in emission field inventory is also considered. Uncertainty assessment is based on the Monte Carlo technique where the regional scale CALPUFF model is the main forecasting tool used in air quality analysis.

2

Metrological Analysis of Precision of the System of Delivering a Water Capsule for Explosive Production of Water Aerosol

100%

Śmigielski G. , Toczek W. , Dygdała R. , Stefański K.

Metrology and Measurement Systems

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2016

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tom Vol. 23, nr 1

47--58

EN

In this paper precision of the system controlling delivery by a helicopter of a water capsule designed for extinguishing large scale fires is analysed. The analysis was performed using a numerical method of distribution propagation (the Monte Carlo method) supplemented with results of application of the uncertainty propagation method. In addition, the optimum conditions for the airdrop are determined to ensure achieving the maximum area covered by the water capsule with simultaneous preserving the precision level necessary for efficient fire extinguishing.

3

Measurement Uncertainty In Algorithms Using PCA Method

100%

Augustyn J.

Measurement Automation Monitoring

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2015

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tom Vol. 61, No. 11

494--497

EN

Propagation analysis of selected uncertainty sources in algorithms using the PCA method has been presented. The paper shows uncertainty analysis in algorithms, which use minimization of squared distances technique and maximizing the variance technique. On the basis of simulation tests the influence of the used signal sampling technique on the eigenvalues vector for the sinusoidal signal containing additive white noise, has been compared. Three applied sampling techniques have been analyzed: synchronization of the beginning of the data acquisition, for the successive sequences xi, immediately after a positive zero-level crossing of the analyzed waveform; separation of the NM-element sequence x to M of N-element sequences xi collected sequentially in subsequent rows of the matrix X; and application of sampling with the fractional delay of d=Ts/2, and X matrix construction from alternating strings: x2i-1 - sampled with a delay of d, and x2i - sampled with a zero delay from the moment of the zero crossing by analyzed waveform.

4

Measurement of basic observation parameters of optoelectronic devices in an accredited laboratory. Measurement methodology, uncertainty analysis

100%

Bareła J. , Kastek M. , Firmanty K.

Measurement Automation Monitoring

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2019

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tom Vol. 65, No. 1

2--6

EN

The article describes the methodologies for measuring the basic parameters of optoelectronic observation devices in accordance with applicable standards and international procedures. Noise equivalent temperature difference NETD, minimum resolvable temperature difference MRTD, detection, recognition and identification ranges according to STANAG 4347, angular field of view FOV and modulation transfer function MTF are described. The description and requirements for laboratory measuring stations are presented. The article contains an analysis of measurement uncertainty of measured quantities in accordance with ISO 17025: 2018 and JCGM 100: 2008 guide based on the TOP 6-3-040 procedure.

5

Uncertainty analysis of the kinetic model of natural gas combustion in IC Engine

100%

Mansha M. , Naqvi J.

Polish Journal of Chemical Technology

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2012

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tom 14

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nr 1

1-4

EN

The purpose of this analysis is to determine the uncertainties originating due to the kinetic parameters of the rate of a reaction proposed kinetic model. A kinetic model consisting of 208 reaction steps and 73 species was adopted for analysis. In the required uncertainty analysis, the accuracy of approximate models, generated by the Chemkin 4.1.1 for pollutant species, is determined. The reactions which contribute the uncertainty in the output concentrations of the pollutnats species formed in the combustion chamber were identified. The percentage contribution to the uncertainty in the output concentrations of pollutants were also determined.

6

Application of uncertainty analysis in structural dynamics

88%

Martowicz A. , Pieczonka Ł. , Uhl T.

Journal of KONES

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2008

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tom Vol. 15, No. 1

153-167

EN

The paper deals with the application of uncertainty analysis in structural dynamics. The usage of soft computing method, namely Genetic Algorithms (GA), is presented to show effective computational technique that allows for assessing the propagation of defmed uncertainties in modelled mechanical structure. Tested method is capable of finding variation of eigenfrequencies of Finite Element models and is based on scanning of interval global system matrices. During this process combination of values of input design parameters are found for which extremes of frequencies of vibration appear. FE model of windscreen, made available by Renault Technocentre, has been anafysed. Assumed uncertainties have taken. into account variability of material properties, geometrical characteristics and environmental conditions. Fuzzy theory together with alpha-cut strategy has been applied for modelling uncertain parameters. Sensitivity analysis has been performed to investigate the contribution effect introduced by each assumed input parameter to studied frequency of vibration. Obtained results have been presented and discussed within the context of referential results yielded from Monte Carlo simulation and GA used directly for the search of frequency extremes. Finally, observed time savings have been mentioned to justify the usage of tested computational method.

7

Filtered thermal contrast based technique for testing of material by infrared thermography

88%

Gryś S.

Opto-Electronics Review

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2011

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tom Vol. 19, No. 2

234-241

EN

A new kind of thermal contrast, called ''filtered contrast'' is presented, which allows detecting and characterizing material defects using active thermography under some assumptions on physical and thermal parameters of materials. In opposition to known definitions of the thermal contrast, knowledge about defect-free area is not necessary and this contrast is less sensitive to nonuniformity of heat disposal to the material surface. The measurements were performed on an experimental setup equipped with a ThermaCAM PM 595 infrared camera and frame grabber. The step heating was chosen as heat excitation. The results demonstrate usefulness of the 1D model of heat transfer used for determination of depth of subsurface defects. The influence of the parameter of the smoothing filter, required for filtered contrast implementation, thermal parameters of the tested material and defect on expanded uncertainty of determination of defect depth is also presented. Due to significant complexity of the model of heat transfer, the conditions for the "law of propagation of uncertainty" were not fulfilled and a numerical method, i.e., Monte Carlo simulation is applied for the propagation of distributions.

8

Metrological Analysis of Precision of the System of Delivering a Water Capsule for Explosive Production of Water Aerosol

88%

Śmigielski G. , Stefański K. , Toczek W. , Dygdała R.

|

nr 1

9

Modelling of solute transport in rivers under different fflow rates: A case study without transient storage

88%

Romanowicz R. J. , Osuch M. , Wallis S.

Acta Geophysica

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2013

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tom Vol. 61, no. 1

98--125

EN

A methodology to derive solute transport models at any flow rate is presented. The novelty of the proposed approach lies in the assessment of uncertainty of predictions that incorporate parameterisation based on flow rate. A simple treatment of un certainty takes in to account hetero- scedastic modelling errors related to tracer experiments performed over a range of flow rates, as well as the uncertainty of the observed flow rates themselves. The proposed approach is illustrated using two models for the transport of a conservative solute: a physically based, deterministic, advection-dispersion model (ADE), and a stochastic, transfer function based, active mixing volume model (AMV). For both models the uncertainty of any parameter increases with increasing flow rate (reflecting the heteroscedastic treatment of modelling errors at different observed flow rates), but in contrast the uncertainty of travel time, computed from the predicted model parameters, was found to decrease with increasing flow rate.

10

Automatic defect detection and characterization by thermographic images based on damage classifiers evaluation

88%

Dinardo G. , Fabbiano L. , Tamborrino R. , Vacca G.

Metrology and Measurement Systems

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2020

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tom Vol. 27, nr 2

219--242

EN

In the framework of non-destructive evaluation (NDE), an accurate and precise characterization of defects is fundamental. This paper proposes a novel method for characterization of partial detachment of thermal barrier coatings from metallic surfaces, using the long pulsed thermography (LPT). There exist many applications, in which the LPT technique provides clear and intelligible thermograms. The introduced method comprises a series of post-processing operations of the thermal images. The purpose is to improve the linear fit of the cooling stage of the surface under investigation in the logarithmic scale. To this end, additional fit parameters are introduced. Such parameters, defined as damage classifiers, are represented as image maps, allowing for a straightforward localization of the defects. The defect size information provided by each classifier is, then, obtained by means of an automatic segmentation of the images. The main advantages of the proposed technique are the automaticity (due to the image segmentation procedures) and relatively limited uncertainties in the estimation of the defect size.

11

Determination of transient fluid temperature using the inverse method

75%

Jaremkiewicz M.

Archives of Thermodynamics

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2014

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tom Vol. 35, no. 1

61--76

EN

This paper proposes an inverse method to obtain accurate measurements of the transient temperature of fluid. A method for unit step and linear rise of temperature is presented. For this purpose, the thermometer housing is modelled as a full cylindrical element (with no inner hole), divided into four control volumes. Using the control volume method, the heat balance equations can be written for each of the nodes for each of the control volumes. Thus, for a known temperature in the middle of the cylindrical element, the distribution of temperature in three nodes and heat flux at the outer surface were obtained. For a known value of the heat transfer coefficient the temperature of the fluid can be calculated using the boundary condition. Additionally, results of experimental research are presented. The research was carried out during the start-up of an experimental installation, which comprises: a steam generator unit, an installation for boiler feed water treatment, a tray-type deaerator, a blow down flashvessel for heat recovery, a steam pressure reduction station, a boiler control system and a steam header made of martensitic high alloy P91 steel. Based on temperature measurements made in the steam header using the inverse method, accurate measurements of the transient temperature of the steam were obtained. The results of the calculations are compared with the real temperature of the steam, which can be determined for a known pressure and enthalpy.

12

Ocena błędów granicznych pomiarów wad w diagnostyce ultradźwiękowej

75%

Lesiak P. , Warsza Z. L.

Przegląd Elektrotechniczny

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2006

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tom R. 82, nr 12

11-19

PL

Podano podstawowe zależności opisujące położenie i rozmiary wady jako lokalnej wewnętrznej nieciągłości materiału, otrzymywane w ultradźwiękowych badaniach defektoskopowych metodą echa z pomiarów czasu powrotu i amplitudy wiązki fal odbitej od jej brzegu. Wiązkę tę emituje cyklicznie skośna głowica nadawczo-odbiorcza przesuwana po powierzchni badanego obiektu sprzężona z nim akustycznie. Wyznaczono wzory błędów bieżących i granicznych dla ciągłych i dyskretnych położeń głowicy. Rozważania poparto symulacją komputerową opartą na danych z praktyki. Przedstawiono przykład, w którym po oszacowaniu błędów granicznych rozciągu wady wykrytej w automatycznym badaniu ultradźwiękowym należało zmienić jej kwalifikację.

EN

Basic equations of the position coordinates and dimensions of flaw in form of the local internal material discontinuity are given. These flaw variables are obtained from the measurement of return time and amplitude of the ultrasonic inspection beam emitted and detected by inclined head sliding on the object surface and acoustically coupled with it. Emissions are made cyclically in positions of the ultrasonic head changed continuously or by quantized steps and beam is reflected from the flaw boundary on its way. Formulas of instant and limited systematic errors as measures of above measurements for continue and discrete head positions are given. Considerations are supported by computer simulation and the case taken from practice, when classification as "save" of the detected automatically flaw has to be changed after estimation of its length limited error's.

13

Analysis of uncertainties in MEMS and their influence on dynamic properties

75%

Uhl T. , Martowicz A. , Codreanu I. , Klepka A.

Archives of Mechanics

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2009

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tom Vol. 61, nr 5

349-370

EN

An application of uncertainty analysis of microelectromechanical resonator is presented. A number of different uncertain parameters have been considered, connected both to geometric characteristics and material property. Sensitivity analysis has been carried out in order to study the influence of each input uncertain parameter on the chosen dynamic characteristics. The propagation of given uncertainties into the variation of studied output parameter has been evaluated by means of the Monte Carlo simulation, the vertex method and genetic algorithms. Finite element model of microresonator has been elaborated. It has taken into account the phenomenon of viscous damping coming from the presence of surrounding air as well as the in?uence of constant electrostatic field.

14

Automatic defect detection and characterization by thermographic images based on damage classifiers evaluation

75%

Dinardo G. , Fabbiano L. , Tamborrino R. , Vacca G. , Dinardo G. , Fabbiano L. , Tamborrino R. , Vacca G.

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15

Analiza niepewności w ocenie zgodności metrologicznej gazomierzy ultradźwiękowego i zwężkowego

75%

Dyakowska E.

Pomiary Automatyka Robotyka

|

2002

|

tom R. 6, nr 12

16-20

PL

Na podstawie porównania wskazań pracujących szeregowo gazomierzy ultradźwiekowego i zwężkowego oszacowano dopuszczalną różnicę strumienia objetości gazu mierzonego gazomierzami obu rodzajów. Zastosowano w tym celu analizę niepewnosci. Współczynniki wrażliwości obliczono metodą numeryczną.

EN

Comparison of indications of gas meters working in series enables to assess their performance. In the paper permissible difference between measurement results of gas volume flow rate, measured by ultrasonic and orifice gas meters was estimated. For the estimation uncertainty analysis was used. Sensitivity coefficients were calculated numerically.

16

Application of uncertainty analysis based on Monte Carlo (MC) simulation for life cycle inventory (LCI)

75%

Sala D. , Bieda B.

Inżynieria Mineralna

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2019

|

tom R. 21, nr 2/2

264--269

EN

The use of Monte Carlo (MC) simulation was presented in order to assess uncertainty in life cycle inventory (LCI) studies. The MC method is finded as an important tool in environmental science and can be considered the most effective quantification approach for uncertainties. Uncertainty of data can be expressed through a definition of probability distribution of that data (e.g. through standard deviation or variance). The presented case in this study is based on the example of the emission of SO2, generated during energy production in Integrated Steel Power Plant (ISPP) in Kraków, Poland. MC simulation using software Crystal Ball® (CB), software, associated with Microsoft® Excel, was used for the uncertainties analysis. The MC approach for assessing parameter uncertainty is described. Analysed parameter (SO2,) performed in MC simulation were assigned with log-normal distribution. Finally, the results obtained using MC simulation, after 10,000 runs, more reliable than the deterministic approach, is presented in form of the frequency charts and summary statistics. Thanks to uncertainty analysis, a final result is obtained in the form of value range. The results of this study will encourage other researchers to consider this approach in their projects, and the results of this study will encourage other LCA researchers to consider the uncertainty in their projects and bring closer to industrial application.

17

Reduction of dynamic error in measurements of transient fluid temperature

63%

Jaremkiewicz M.

Archives of Thermodynamics

|

2011

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tom Vol. 32, no. 4

55-66

EN

Under steady-state conditions when fluid temperature is constant, temperature measurement can be accomplished with high degree of accuracy owing to the absence of damping and time lag. However, when fluid temperature varies rapidly, for example, during start-up, appreciable differences occur between the actual and measured fluid temperature. These differences occur because it takes time for heat to transfer through the heavy thermometer pocket to the thermocouple. In this paper, a method for determinig transient fluid temperature based on the first-order thermometer model is presented. Fluid temperature is determined using a thermometer, which is suddenly immersed into boiling water. Next, the time constant is defined as a function of fluid velocity for four sheated thermocouples with different diameters. To demonstrate the applicability of the presented method to actual data where air velocity varies, the temperature of air is estimated based on measurements carried out by three thermocouples with different outer diameters. Lastly, the time constant is presented as a function of fluid velocity and outer diameter of thermocouple.

18

Fluid temperature measurement under transient conditions

63%

Taler J. , Jaremkiewicz M. , Taler D. , Sobota T.

Archives of Thermodynamics

|

2009

|

tom Vol. 30, no. 3

75-88

EN

Under steady-state conditions when fluid temperature is constant, there is no damping and time lag and temperature measurement can be accomplished with high degree of accuracy. However, when fluid temperature is varying rapidly as during start-up, quite appreciable differences occur between the actual fluid temperature and the measured temperature. This is due to the time required for the transfer of heat to the thermocouple placed inside a heavy thermometer pocket. In this paper, two different techniques for determining transient fluid temperature based on the first and second order thermometer model are presented. The fluid temperature was determined using the temperature indicated by the thermometer, which was suddenly immersed into boiling water. To demonstrate the applicability of the presented method to actual data, the time constant of the sheathed thermocouple placed in the air stream was estimated as a function of the air velocity.

19

Intelligent velocity picking and uncertainty analysis based on the Gaussian mixture model

63%

Wang X. , Gao Y. , Chen C. , Yuan H. , Yuan S.

Acta Geophysica

|

2022

|

tom Vol. 70, no 6

2659--2673

EN

The stacking velocity is often obtained manually. However, manually picking is inefficient and is easily affected by subjective factors such as the priori information and the experience of different processors. To enhance its objectivity, efficiency and consistency, we investigated an unsupervised clustering intelligent velocity picking method based on the Gaussian mixture model (GMM). This method can automatically pick the stacking velocity fast, and provide uncertainty analysis as a quality control. Combined with the geometry feature of energy clusters in velocity spectra, taking advantages of the geometric diversity of energy clusters, GMM can ft the energy clusters with different distributions more appropriately. Then, mean values of the final several submodels are located as the optimal velocity, and the multiples are avoided under the expert knowledge and geological rules. In addition, according to the covariance of submodels, we can derive the uncertainty analysis of the final time-velocity pairs, so as to indicate the reliability of picking velocity at different depths. Moreover, the automated interpreted velocity field is used for both normal moveout (NMO) correction and stacking. The comparison with the manual references is adopted to evaluate the quality of the unsupervised clustering intelligent velocity picking method. Both synthetic data and 3D field data have shown that the proposed unsupervised intelligent velocity picking method can not only achieve similar accuracy with manual results, but also get rid of multiples. Furthermore, compared with manual picking, it can significantly improve the efficiency and accuracy in identifying pore and cave structures, as well as indicating the uncertainty of time-velocity pairs by variance.

20

Analiza elementów ryzyka geologicznego rejonu Suliszewo–Radęcin w kontekście składowania CO2

63%

Michna M. , Papiernik B.

Biuletyn Państwowego Instytutu Geologicznego

|

2012

|

tom nr 448 (1)

81--86

PL

Artykuł skupia się na analizie elementów ryzyka dolnojurajskiej formacji zawodnionej w rejonie Radęcin–Suliszewo. Skałami zbiornikowymi są tutaj piaskowce synemuru oraz pliensbachu a uszczelniają je mułowce i iłowce toarku. Autorzy stworzyli model strukturalny a następnie bazowe modele parametryczne rejonu Radęcin–Suliszewo. Na podstawie modeli bazowych oszacowano wyjściową wartość możliwego do zatłoczenia CO2. W kolejnym etapie, używając procedury Uncertainty Analysis w programie Petrel dokonano analizy czterech elementów niepewności (nasycenia gazem, położenia kontaktu woda/gaz, porowatości, proporcji skał zbiornikowych do uszczelniających) wpływających na wartości wolumetryczne. Określono rozkład oraz zakres poszczególnych elementów niepewności. Dzięki symulacji metodą Monte Carlo wykonano losowanie prób dla wymienionych parametrów niepewności. Dla każdej realizacji wyliczono objętość gazu w warunkach złożowych.Wyniki przedstawiono w postaci histogramów oraz wykresu tornado. W ten sposób określono, w jakim stopniu poszczególne elementy niepewności wpływają na ilość CO2 możliwego do zmagazynowania. Największy wpływ na ilość możliwego do zmagazynowania gazu ma odpowiednio założony model nasycenia gazem (93–116% względem modelu bazowego) następnie określony kontakt między mediami złożowymi (93,5–106,5% względem modelu bazowego). Porowatość wpływa w tym przypadku w granicy 97–103,5% na wyniki analizy, natomiast różnica w progowej wartości skały zbiornikowe/skały uszczelniające jest nieznaczna i można ją zaniedbać.

EN

The paper presents the analysis of risk elements in the Lower Jurassic water-saturated formation in the Radęcin–Suliszewo area. The reservoir rocks in this area are represented by Sinemurian and Pliensbachian sandstones sealed by Toarcian mudstones and claystones. The authors constructed a structural model and then base parametric models for the Radęcin–Suliszewo area. Based on the base models, an output value of the CO2 amount possible to be injected was estimated. In the next stage, following the Uncertainty Analysis procedure in Petrel, analysis of four elements affecting volumetric values was carried out (i.e. gas saturation, location of gas/water contact, porosity, and the ratio of reservoir rocks versus sealing rocks). With ap.lication of the Monte Carlo method, sampling for the above uncertainty elements was performed. For each realization, gas volume in reservoir conditions was computed. The results were presented in the form of histograms and a tornado chart. In this way, the authors determined to what degree the individual uncertainty elements affect the CO2 amount possible to be injected. The strongest effects on the amount are associated with the properly assumed model of gas saturation (93–116% in relation to the base model) and then the determined contact between reservoir media (93.5–106.5% in relation to the base model). Porosity affects from 97–103.5% of the analysis results and the difference in the threshold value of the reservoir rocks/sealing rocks ratio is insignificant and can be neglected.