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1
Content available Bootstrapping the empirical bounds on the variability of Sample Entropy in 24-hour ECG recordings for 1 hour segments
Zurek S., Grabowski W., Kosmider M., Jurga S., Guzik P., Piskorski J.
Journal of Applied Mathematics and Computational Mechanics
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2018
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Vol. 17, nr 2
105--113
EN
We investigate the variability of one of the most often used complexity measures in the analysis of the time series of RR intervals, i.e. Sample Entropy. The analysis is carried out for a dense matrix of possible r thresholds in 79 24h recordings, for segments consisting of 5000 consecutive beats, randomly selected from the whole recording. It is repeated for the same recordings in random order. This study is made possible by the novel NCM algorithm which is many orders of magnitude faster than the alternative approaches. We find that the bootstrapped standard errors for Sample entropy are large for RR intervals in physiological order compared to the standard errors for shuffled data which correspond to the maximum available entropy. This result indicates that Sample Entropy varies widely over the circadian period. This paper is purely methodological and no physiological interpretations are attempted.
2
Content available Asymmetric detrended fluctuation analysis reveals asymmetry in the rr intervals time series
Mieszkowski D., Kośmider M., Krauze T., Guzik P., Piskorski J.
Journal of Applied Mathematics and Computational Mechanics
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2016
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Vol. 15, nr 1
99--106
EN
In this paper we apply the Asymmetric Detrended Fluctuation Analysis to the RR intervals time series. The mathematical background of the ADFA method is discussed in the context of heart rate variability and heart rate asymmetry. We calculate the α- and α+ ADFA scaling exponents for 100 RR intervals time series recorded in a group of healthy volunteers (20-40 years of age) with the use of the local ADFA. It is found that on average α+ < α-, and that locally α- dominates most of the time over α+ - both results are highly statistically significant.
3
Content available Language resources for named entity annotation in the National Corpus of Polish
Savary A., Piskorski J.
Control and Cybernetics
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2011
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Vol. 40, no 2
361-391
EN
We present the named entity annotation subtask of a project aiming at creating the National Corpus of Polish. We summarize the annotation requirements defined for this corpus, and we discuss how existing lexical resources and grammars for named entity recognition for Polish have been adapted to meet those requirements. We show detailed results of the corpus annotation using the information extraction platform SProUT. We also analyze the errors committed by our knowledge-based method and suggest its further improvements.
4
Content available remote Long Time Deviations from the Exponential Decay Law: Possible Observational Effects
Urbanowski K., Piskorski J.
Computational Methods in Science and Technology
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2010
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Vol. 16, No. 2
201-205
EN
An effect generated by the nonexponential behavior of the survival amplitude of an unstable state in the long time region is considered. We find that the instantaneous energy of the unstable state for a large class of models of unstable states tends to the minimal energy of the system epsilon min as t rightwards arrow infinity which is much smaller than the energy of this state for t of the order of the lifetime of the considered state. Analyzing the transition time region between the exponential and non-exponential form of the survival amplitude, we find that the instantaneous energy of the considered unstable state can take large values, much larger than the energy of this state for t from the exponential time region. Taking into account results obtained for a considered model, it is hypothesized that this purely quantum mechanical effect may be responsible for the properties of broad resonances such as sigma meson as well as having astrophysical and cosmological consequences.
5
Content available remote Dynamic Decomposition of Poincaré Plots for Multivariate Analysis and Visualization of Simultaneously Recorded Physiological Time Series
Piskorski J., Guzik P.
Computational Methods in Science and Technology
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2010
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Vol. 16, No. 2
181-186
EN
We apply the dynamic decomposition of Poincaré plots, which is a computationally intensive, visual method of analysing physiological time series, to the analysis of the interbeat interval variability, systolic blood pressure, stroke volume and total peripheral resistance which were simultaneously recorded from a patient with pheochromocytoma and rapid, repetitive haemodynamic changes over 6 hours. The resulting animation is analysed and interpreted. It is found that changes in total peripheral resistance usually precede those of other variables, and the magnitude of changes is greatest for this variable. It is demonstrated that the decomposition of Poincaré plots of multivariate signals can visualise both the order and the extent of ongoing instant changes.
6
Content available remote An Exploratory Clustering Study of Rare Adverse Events in Drug Eluting Stents Patients
Bychowiec B., Piskorski J., Stanislawska K., Dziarmaga M., Minczykowski A., Wykretowicz A., Wysocki H.
Computational Methods in Science and Technology
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2010
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Vol. 16, No. 1
5-11
EN
We present an exploratory study of a group of patients (150) who have undergone precutaneous transluminal coronary angioplasty with the use of drug eluting stents. We concentrate on the most often studied rare adverse event, i.e. death, as well as the still unexplored cancer variable. The aim of the study is to identify possible statistical hypotheses for a subsequent, large sample study. The results of this study may lead to a change in the therapy administered after precutaneous coronary interventions which will reduce the mortality rate. To achieve this, we use clustering techniques such as hierarchical cluster analysis, principal components methods and interactive brushing. We show that death cases cluster in the space defined by the available variables, while the cancer cases do not seem to cluster.
7
Content available remote Filtering Poincaré plots
Piskorski J., Guzik P.
Computational Methods in Science and Technology
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2005
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Vol. 11, nr 1
39-48
EN
The Poincaré plot (PP) is one of the many techniques used for ascertaining the heart rate variability, which in turn is a marker of the activity of the autonomic system. Poincaré plots are very simple to produce, but their preparation involves a few fine points. This paper describes one of them, namely the filtering of data used for the Poincaré plot. We show the correct way of filtering data, present a few results of not filtering or incorrect filtering and demonstrate how proper filtering helps extract interesting information from the data. A few algorithms for preparing Poincaré plots, filtering data and calculating PP descriptors are included. As Matlab’s programming language is the unquestionable standard for data analysis in the medical sciences, we illustrate these algorithms by snippets of code in this language.
8
Content available remote Experiments on classification of Polish newspaper articles
Piskorski J., Sydow M.
Archives of Control Sciences
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2005
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Vol. 15, no. 4
625-636
EN
This article reports on some experiments on automatic classification of Polish newspaper articles. In particular, we explore two alternative approaches, one based on development of linguistic features and second involving purely language-independent character-level n-gram modelling. Extensive evaluation results are presented. Interestingly, both the, very diffrent, methods exhibit comparable classification performance.
9
Sanockie doświadczenia w odsiarczaniu gazu ziemnego metodą chelatową
Król Z., Ołowski J., Piskorski J.
WUG : bezpieczeństwo pracy i ochrona środowiska w górnictwie
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2000
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nr 8
28-32
PL
Wsród współczesnych technologii odsiarczania gazu ziemnego przydatnych dla niewielkich obiektów wyróżniają się korzystne metody "Redox", których produktem końcowym jest siarka elementarna. Spośród nich szczególnie szybko rozwijają się technologie wykorzystujące chelaty żelaza (Fe-EDTA) jako katalizator konwersji H2S do siarki. Artykuł prezentuje wyniki testowania i wdrożenia w O/SZGNiG Sanok krajowej odmiany chelatowej technologii odsiarczania opracowanej przez IGNiG Kraków, znanej pod nazwą IGNiG-Chelate.
EN
Among the contemporary natural gas desulfurization technological processes that are suitable for rather small-size plants, distinguished as advantageous are the "Redox" methods with elementary sulphur as the final product. Out of them, the technological processes that utilize iron chelates (Fe-EDTA) as a catalyzer of conversion of H2S to elemental sulphur undergo a particularly rapid development. The article presents the results of testing and implementation, in the O/SZGNiG Sanok, of a domestic modification of the chelate Desulfurization technology, known under the name of IGNiG-Chelate, developed by the Purification and Odorizing Unit of the Institute of Oil Mining & gas Engineering - Warsaw Branch /Zakład Technologii Oczyszczania i Nawadniania, Instytut Górnictwa Naftowego i Gazownictwa - Oddział w Warszawie/.
10
Content available remote Doświadczenia O/SGNiG Sanok w odsiarczaniu gazu ziemnego metodą IGNiG-Chelate
Król Z., Ołowski J., Piskorski J.
Nafta-Gaz
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1999
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R. 55, nr 5
253--259
PL
Wśród współczesnych technologii odsiarczania gazu ziemnego przydatnych dla niewielkich obiektów wyróżniają się korzystnie metody "Redox", których produktem końcowym jest siarka elementarna. Spośród nich szczególnie szybko rozwijają się technologie wykorzystujące jako katalizator konwersji H2S do siarki chelaty żelaza (Fe-EDTA). Artykuł prezentuje wyniki testowania i wdrożenia w O/SZGNiG Sanok krajowej odmiany chelatowej technologii odsiarczania, znanej pod nazwą IGNiG-Chelate opracowanej przez Zakład Technologii Oczyszczania i Nawaniania Instytutu Górnictwa Naftowego i Gazownictwa - Oddział w Warszawie.
EN
Giving elementary sulfur as the final product, Redox methods have been found especially favourable to desulfurize natural gases in small plants. And among them the most promising are the processes where iron chelates are used as catalysts to convert H 2S into sulfur. The paper reports some results of tests on implementation of a Polish version of the technology, known as IGNiG-Chelate method. It has been developed by Department of Purification and Odorization Technologies in Oil and Gas Institute Subsidiary in Warsaw.
11
Content available remote Instalacja odsiarczania metodą IGNiG Chelate na KGZ Tarnów I
Ołowski J., Piskorski J., Marek Z.
Wiadomości Naftowe i Gazownicze
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1998
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R. 1, Nr 7 (7)
9-11
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