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Analýza korozního poškození potrubí s proudící párou pomocí akustické emise:\nteoretická východiska a první výsledky
Tichavský, Petr
2017 - Czech
Zpráva popisuje první vysledky analýzy dat akustické emise získané měřením na parovodním potrubí v Atomové elektrárně Jaslovské Bohunice pořízené za účelem zkoumání korozního poškození potrubí. The report describes the first results of the analysis of the acoustic emission data obtained by measuring the steam pipeline at the Jaslovské Bohunice Atomic Power Plant, which was made for the purpose of investigation of corrosion damage to the pipeline.
Keywords:
acoustic emission
Fulltext is available at external website.
Analýza korozního poškození potrubí s proudící párou pomocí akustické emise:\nteoretická východiska a první výsledky
Zpráva popisuje první vysledky analýzy dat akustické emise získané měřením na parovodním potrubí v Atomové elektrárně Jaslovské Bohunice pořízené za účelem zkoumání korozního poškození ...
Various Approaches to Szroeter’s Test for Regression Quantiles
Kalina, Jan; Peštová, B.
2017 - English
Regression quantiles represent an important tool for regression analysis popular in econometric applications, for example for the task of detecting heteroscedasticity in the data. Nevertheless, they need to be accompanied by diagnostic tools for verifying their assumptions. The paper is devoted to heteroscedasticity testing for regression quantiles, while their most important special case is commonly denoted as the regression median. Szroeter’s test, which is one of available heteroscedasticity tests for the least squares, is modified here for the regression median in three different ways: (1) asymptotic test based on the asymptotic representation for regression quantiles, (2) permutation test based on residuals, and (3) exact approximate test, which has a permutation character and represents an approximation to an exact test. All three approaches can be computed in a straightforward way and their principles can be extended also to other heteroscedasticity tests. The theoretical results are expected to be extended to other regression quantiles and mainly to multivariate quantiles.
Keywords:
Heteroscedasticity; Regression median; Diagnostic tools; Asymptotics
Fulltext is available at external website.
Various Approaches to Szroeter’s Test for Regression Quantiles
Regression quantiles represent an important tool for regression analysis popular in econometric applications, for example for the task of detecting heteroscedasticity in the data. Nevertheless, they ...
Flexible Moment Invariant Bases for 2D Scalar and Vector Fields
Bujack, R.; Flusser, Jan
2017 - English
Complex moments have been successfully applied to pattern detection tasks in two-dimensional real, complex, and vector valued functions. In this paper, we review the different bases of rotational moment invariants based on the generator approach with complex monomials. We analyze their properties with respect to independence, completeness, and existence and\npresent superior bases that are optimal with respect to all three criteria for both scalar and vector fields.
Keywords:
Pattern detection; moment invariants; scalar fields; vector fields; flow fields; generator; basis; complex; monomial
Fulltext is available at external website.
Flexible Moment Invariant Bases for 2D Scalar and Vector Fields
Complex moments have been successfully applied to pattern detection tasks in two-dimensional real, complex, and vector valued functions. In this paper, we review the different bases of rotational ...
Odhad rychlosti šíření akustických vln ve vzorku oceli pro sledování creepových změn pomocí akustické emise
Tichavský, Petr; Slunéčko, T.; Svobodová, M.; Chmela, T.
2017 - Czech
Zpráva popisuje měření rychlosti šíření zvuku ve vzorku materiálu podrobeném tepelnému a mechanickému namáhání pomocí signálu akustické emise. The report describes the measurement of the sound propagation velocity in a sample of material subjected to heat and mechanical stress by means of an acoustic emission.
Keywords:
sound propagation
Fulltext is available at external website.
Odhad rychlosti šíření akustických vln ve vzorku oceli pro sledování creepových změn pomocí akustické emise
Zpráva popisuje měření rychlosti šíření zvuku ve vzorku materiálu podrobeném tepelnému a mechanickému namáhání pomocí signálu akustické emise....
Avoiding overfitting of models: an application to research data on the Internet videos
Jiroušek, Radim; Krejčová, I.
2017 - English
The problem of overfitting is studied from the perspective of information theory. In this context, data-based model learning can be viewed as a transformation process, a process transforming the information contained in data into the information represented by a model. The overfitting of a model often occurs when one considers an unnecessarily complex model, which usually means that the considered model contains more information than the original data. Thus, using one of the basic laws of information theory saying that any transformation cannot increase the amount of information, we get the basic restriction laid on models constructed from data: A model is acceptable if it does not contain more information than the input data file.
Keywords:
data-based learning; probabilistic models; information theory; MDL principle; lossless encoding
Fulltext is available at external website.
Avoiding overfitting of models: an application to research data on the Internet videos
The problem of overfitting is studied from the perspective of information theory. In this context, data-based model learning can be viewed as a transformation process, a process transforming the ...
Causality and Intervention in Business Process Management
Bína, V.; Jiroušek, Radim
2017 - English
The paper presents an algebraic approach to the modeling of causality in systems of stochastic variables. The methodology is based on an operator of a composition that provides the possibility of composing a multidimensional distribution from low-dimensional building blocks taking advantage of the dependence structure of the problem variables. The authors formally define and demonstrate on a hypothetical example a surprisingly elegant unifying approach to conditioning by a single variable and the evaluation of the effect of an intervention. Both operations are realized by the composition with a degenerated distribution and differ only in the sequence in which the operator of the composition is performed.
Keywords:
Compositional model; Operator of composition,; Causality; Conditioning; Intervention
Fulltext is available at external website.
Causality and Intervention in Business Process Management
The paper presents an algebraic approach to the modeling of causality in systems of stochastic variables. The methodology is based on an operator of a composition that provides the possibility of ...
Metodika ultrazvukového vyšetření prsou
Vydra, J.; Daneš, J.; Bartoš, Michal; Šroubek, Filip; Petr, L.; Zitová, Barbara
2017 - Czech
Cílem projektu je vývoj nového ultrazvukového diagnostického zařízení (UZ), které umožní časný záchyt karcinomu prsu a sníží nutnost požívat ionizující záření při vyšetření. Cílem je odstranit nevýhody současných ultrazvukových diagnostických přístrojů v diagnostice rakoviny prsu, které brání v jeho využití. Mezi cílové parametry patří vyhledávání ložisek a jejich automatizovaný popis pomocí parametrů (rozměry, textura), tedy popis situace, který je schopen vypovídat o nemoci, skládání jednotlivých obrazů (registrace) vedoucí k vytvoření 3D zobrazení - a tím zaručit reprodukovatelnost UZ obrazení a jistotu vyšetření celého orgánu. Zároveň nově vyvinuté ultrazvukové sondy umožní lepší záchyt charakteristických ložisek včetně mikrokalcifikací. Softwarové řešení umožnuje sledovat pohyb sondy a vyhodnocovat kvalitu pokrytí vyšetřšní prsu. The aim of the proposed project is the development of a new ultrasonic equipment (US), allowing early detection of breast cancer and reduce the need to use the ionizing radiation during examinations. The aim is to eliminate the disadvantages of current ultrasonic systems in the diagnosis of breast cancer, which hinders its use. The target parameters include prospecting and automated description using parameters (size, texture), description of the situation, which is able to testify about the disease, combining individual images (registration) leading to the creation of 3D display - thus ensuring reproducibility UZ shaping and security testing the entire organ. At the same time the newly developed ultrasonic probe allows better capture the characteristics of bearings including microcalcifications. Software solution enables to follow the coverage of the breast examination. The areas which were omitted are detected and highlighted.
Keywords:
breast ultrasound examination; breast cancer; computer guided diagnosis
Fulltext is available at external website.
Metodika ultrazvukového vyšetření prsou
Cílem projektu je vývoj nového ultrazvukového diagnostického zařízení (UZ), které umožní časný záchyt karcinomu prsu a sníží nutnost požívat ionizující záření při vyšetření. Cílem je odstranit ...
Parametric Optimization and Related Topics XI
Červinka, Michal; Kratochvíl, Václav
2017 - English
Parametric Optimization and Related Topics XI was a conference dedicate to Jiří Outrata on the occasion of his seventieth birthday. The programme for 86 participants from 21 countries was composed of five invited and 77 contributed talks, held in 22 sessions.
Keywords:
Parametric Optimization; Optimization; Equilibrium
Fulltext is available at external website.
Parametric Optimization and Related Topics XI
Parametric Optimization and Related Topics XI was a conference dedicate to Jiří Outrata on the occasion of his seventieth birthday. The programme for 86 participants from 21 countries was composed of ...
Hidden Auto-Conflict in the Theory of Belief Functions
Daniel, M.; Kratochvíl, Václav
2017 - English
Hidden conflicts of belief functions in some cases where the sum of all multiples of conflicting belief masses being equal to zero were observed. Relationships of hidden conflicts and auto-conflicts of belief functions are pointed out. We are focused on hidden auto-conflicts here - on hidden conflicts appearing when three or more numerically same belief functions are combined. Hidden auto-conflict is a kind of internal conflict. Degrees of hidden auto-conflicts and full non-conflictness are defined and analysed. Finally, computational issues of hidden auto-conflicts and non-conflictness are presented.
Keywords:
Belief functions; Dempster-Shafer theory; Uncertainty; Conflicting belief masses; Internal conflict; Auto-conflict; Hidden-conflict
Fulltext is available at external website.
Hidden Auto-Conflict in the Theory of Belief Functions
Hidden conflicts of belief functions in some cases where the sum of all multiples of conflicting belief masses being equal to zero were observed. Relationships of hidden conflicts and auto-conflicts ...
Exact Inference In Robust Econometrics under Heteroscedasticity
Kalina, Jan; Peštová, B.
2017 - English
The paper is devoted to the least weighted squares estimator, which is one of highly robust estimators for the linear regression model. Novel permutation tests of heteroscedasticity are proposed. Also the asymptotic behavior of the permutation test statistics of the Goldfeld-Quandt and Breusch-Pagan tests is investigated. A numerical experiment on real economic data is presented, which also shows how to perform a robust prediction model under heteroscedasticity. Theoretical results may be simply extended to the context of multivariate quantiles
Keywords:
heteroscedasticity; robust statistics; regression; diagnostic tools; economic data
Fulltext is available at external website.
Exact Inference In Robust Econometrics under Heteroscedasticity
The paper is devoted to the least weighted squares estimator, which is one of highly robust estimators for the linear regression model. Novel permutation tests of heteroscedasticity are proposed. Also ...
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