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1
Impact of meteorological data resolution on the results of air quality modeling
Przybyła T.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2014
|
z. 70
83-84
EN
This paper presents the results of air quality modeling which was carried out for various resolution of meteorological data. The air quality assessment was made using in CALPUFF Modeling System.
2
Content available remote Wykorzystanie składowych głównych z normą L1 do filtracji projekcyjnej
Przybyła T.
Przegląd Elektrotechniczny
|
2014
|
R. 90, nr 5
134--137
PL
W niniejszej pracy zaprezentowano zmodyfikowaną metodę nieliniowej filtracji projekcyjnej. Zaproponowana modyfikacja dotyczy problemu wyznaczania podprzestrzeni projekcyjnej. W oryginalnej metodzie filtracji do wyznaczenia podprzestrzeni projekcyjnej wykorzystuje się metodę analizy składowych głównych (PCA), gdzie wykorzystywana jest norma L2. Norma L2 wrażliwa jest na próbki obce, stąd zaproponowano metodę PCA z normą L1 do wyznaczenia podprzestrzeni projekcyjnej jak również do wyznaczenia końcowej wartości próbki sygnału.
EN
The paper presents a modification of nonlinear state-space projections (NSSP) method. The proposed approach deals with the sub-space estimation problem. In the original NSSP method, the principal component analysis (PCA) is used for the sub-space determination. The classical PCA uses L2 norm which is sensitive to outliers. Thus, in this paper the L1 norm PCA is proposed for a sub-space determination as well as for the final value of the processed signal sample
3
An Implementation of Procedure for Screen Out the Puffs in the Massively Parallel Architecture
Przybyła T.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2013
|
z. 69
87--88
EN
This paper presents the performance improvement achievable in Gaussian Puff Model through parallelization of the procedure of screen out the puff. Calculations carried out in the massively parallel architecture allowed to accelerate the calculations associated with the elimination of the puffs in the CALPUFF model.
4
Content available Enancjoselektywna enzymatyczna desymetryzacja katalizowana lipazami. Część II, Optymalizacja warunków reakcji. Związki mezo
Karczmarska-Wódzka A., Kołodziejska R., Tafelska-Kaczmarek A., Przybyła T., Dramiński M.
Wiadomości Chemiczne
|
2013
|
[Z] 67, 9-10
819--841
EN
In the enzymatic asymmetric synthesis, the enzyme allows the desymmetrization of achiral compounds resulting in chiral compounds of high optical purity. Meso compounds (bearing a plane of symmetry) are very important group of compounds used in EEDs (Scheme 1) [1–4]. Similarly to prochiral compounds, selective acylation or hydrolysis of meso substrates leads to optically active products. Most lipases preferentially convert the same enantiomers in the above mentioned types of reaction. This allows the preparation of the both enantiomers of the product in high chemical and optical yield (Scheme 3–20) [35–58]. An effective enzymatic catalysis should be performed under conditions optimal for a biocatalyst performance. Hence, it is essential to select an appropriate reaction medium, the pH, and temperature [6–34]. Optimization of the reaction conditions in terms of an appropriate solvent selection is effective and most frequently the simplest way to modify the enzyme selectivity. One of the most important criteria for the solvent selection is its nature [25]. The enzyme selectivity is conditioned by its conformational rigidity, which increases in more hydrophobic medium (typical hydrophobic solvents, scCO2). A hydrophobic solvent decreases biocatalyst lability, which does not allow the connection between the structurally mismatched substrate and the active side of an enzyme [10, 26–31]. Ionic liquids are a separate group of solvents which, despite their high hydrophobicity (logP << 0) and polarity, can constitute an ideal medium for the biotransformation reactions [18–23].
5
Content available Projective filtering based on L1-norm PC
Przybyła T., Wróbel J., Pander T., Czabański R., Jeżewski J., Matonia A.
Journal of Medical Informatics & Technologies
|
2013
|
Vol. 22
79--86
EN
The paper presents a modification of nonlinear state-space projections (NSSP) method. The proposed approach deals with the sub-space estimation problem. In the original NSSP method, the principal component analysis (PCA) is used for the subspace determination. The classical PCA uses L2-norm. It is well known that the L2-norm is sensitive to outliers. Thus, in this paper the L1-norm PCA is proposed a subspace determination. In numerical experiments an analytic signal and real ECG signals are processed with the proposed method. The signals are contaminated with Gaussian distributed noise with different signal to noise ratio (SNR). Obtained results confirm the usefulness of the proposed modification.
6
Content available Fuzzy clustering based methods for nystagmus movements detection in electronystagmography signal
Czabański R., Pander T., Horoba K., Przybyła T.
Journal of Medical Informatics & Technologies
|
2013
|
Vol. 22
277--283
EN
The analysis of optokinetic nystagmus (OKN) provides valuable information about the condition of human vision system. One of the phenomena that is used in the medical diagnosis is optokinetic nystagmus. Nystagmus are voluntary or involuntarily eye movements being a response to a stimuli which activate the optokinetic systems. The electronystagmography (ENG) signal corresponding to the nystagmus has a form of a saw tooth waveform with fast components related to saccades. The accurate detection of the saccades in the ENG signal is the base for the further estimation of the nystagmus characteristic. The proposed algorithm is based on the proper filtering of the ENG signal providing a waveform with amplitude peaks corresponding the fast eyes rotation. The correct recognition of the local maxima of the signal is obtained by the means of fuzzy c-means clustering (FCM). The paper presents three variants of saccades detection algorithm based on the FCM. The performance of the procedures was investigated using the artificial as well as the real optokinetic nystagmus cycles. The proposed method provides high detection sensitivity and allows for the automatic and precise determination of the saccades location in the preprocessed ENG signal.
7
Content available An application of the Lp-norm in robust weighted averaging of biomedical signals
Pander T., Przybyła T., Czabański R.
Journal of Medical Informatics & Technologies
|
2013
|
Vol. 22
71--78
EN
Averaging is one of the basic methods of statistical analysis of experimental data where the response of the system is periodic or quasi-periodic. As long as the noise are Gaussian, the standard averaging leads to good results and effective noise reduction. However, when the distortions have impulsive nature, then such an approach leads to a deterioration of the system. In this case the robust methods should be applied which are characterized by resistance to a statistical sample spoken. In this work a robust averaging method based on the minimization of a scalar criterion function using a Lp-norm functions are presented. The effectiveness of the proposed method was tested in an averaging periods aligned ECG signal cycles in the presence of impulse noise.
8
Content available Detekcja sakkad w sygnale ENG z użyciem grupowania rozmytego
Pander T., Czabański R., Wróbel J., Horoba K., Przybyła T.
Aktualne Problemy Biomechaniki
|
2013
|
z. 7
137--142
PL
Sygnał elektrynystagmograficzny (ENG) z oczopląsem ma postać fali o piłokształtnym kształcie składającym się z fazy wolnej oraz szybkiej. Faza szybka to ruch sakkadyczny gałki ocznej. Skuteczna i dokładna detekcja sakkad ma kluczowe znaczenie w określeniu charakteru oczopląsu. W celu prawidłowej detekcji położenia sakkad sygnał ENG jest filtrowany a maksima lokalne są wykrywane za pomocą rozmytej metody c-średnich. Proponowany algorytm charakteryzuje się dużą czułością i pozwala na automatyczną i precyzyjną lokalizację sakkad w sygnale ENG.
EN
The electronystagmography (ENG) signal corresponding to nystagmus has a form of a saw tooth waveform with fast components related to saccades. The accurate detection of saccades in ENG signal is the base for the further estimation of the nystagmus characteristic. The proposed algorithm is based on the proper filtering of the ENG signal providing a waveform with amplitude peaks corresponding the fast eyes rotation. The correct recognition of the local maxima of the signal is obtained by the means of fuzzy c-means clustering (FCM). The proposed algorithm is highly sensitive and allows for the automatic and precise localization of the saccades in ENG signal.
9
Wykorzystanie języka OpenCl do programowania procesorów masowo równoległych
Przybyła T.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2012
|
z. 67
93-97
PL
W pracy przedstawiono możliwości wykorzystania języka OpenCL do programowania procesorów masowo równoległych. Przedstawiono dostępne technologie, pozwalające wykorzystać wydajność obliczeniową współcześnie produkowanych kart graficznych, ze szczególnym uwzględnieniem OpenCL. Zweryfikowano możliwości technologii GPGPU oraz języka OpenCL, dokonując pomiaru czasu realizacji algorytmu mnożenia macierzy na procesorze CPU i GPU.
10
Vectorizatton in calculations in the massively parallel architecture
Przybyła T.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2012
|
z. 68
55--56
EN
This article presents one of the availabie methods of the OpenCL code optimization by means of use of vectorization. The calculations a performed on three diffcrent platforms, narnely AMD, NVIDIA and Intel. The results shows that use of vector types significantly reduces the execution timc of the algorithm in the massively parallel architecture.
11
Content available The possibilities of optokinetic nystagmus cycles averaging
Pander T., Czabański R., Przybyła T., Pojda-Wilczek D.
Journal of Medical Informatics & Technologies
|
2012
|
Vol. 19
25--31
EN
The analysis of eyes movements is a crucial part of eyes examination performed by clinicians. One of the characteristic type of eyes movements is a saccade. Its accurate detection is the base for further processing including the estimation of saccade parameters such as velocity, amplitude and duration. This paper presents averaging of optokinetic nystagmus (OKN) cycles that allows comparing and detecting different types of nystagmus phenomena. In order to average the OKN cycles the ENG signal needs to be processed. The saccade detection function is used to find the location of saccades in OKN waveform allowing the ENG signal to be divided into cycles. The resulting cycles are aligned using the Fourier shift method and then averaged providing the OKN cycle model, which can be used for evaluating the eyes at different movement conditions.
12
Content available Segmentation of biomedical signals using an unsupervised approach
Przybyła T., Wróbel J., Czabański R., Horoba K., Pander T., Momot M.
Journal of Medical Informatics & Technologies
|
2012
|
Vol. 19
125--131
EN
The paper presents an unsupervised approach to biomedical signal segmentation. The proposed segmentation process consists of several stages. In the first step, a state-space of the signal is reconstructed. In the next step, the dimension of the reconstructed state-space is reduced by projection into principal axes. The final step involves fuzzy clustering method. The clustering process is applied in the kernel-feature space. In the experimental part, the fetal heart rate (FHR) signal is used. The FHR baseline and the acceleration or deceleration patterns are the main signal nonstationarities but also the most clinically important signal features determined and interpreted in computer-aided analysis.
13
Content available Saccades detection in optokinetic nystagmus - a fuzzy approach
Pander T., Czabański R., Przybyła T., Pojda-Wilczek D.
Journal of Medical Informatics & Technologies
|
2012
|
Vol. 19
33--39
EN
The analysis of eye movements is valuable in both clinical work and research. One of the characteristic type of eye movements is saccade. The accurate detection of saccadic eye movements is the base for further processing of saccade parameters such velocity, amplitude and duration. This paper presents an accurate saccade detection method which is supported by the fuzzy clustering. The proposed detection function is computationally efficient and precisely determines the time position of the saccadic eye movement event. The described method is characterized by low sensitivity for any kind of noise and can be applied in the analysis of the congenital nystagmus.
14
Implementation of the intelligent house idea based on the Fatek PLC
Przybyła T.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2011
|
z. 66
73-74
15
Content available Hybrydowy detektor zespołu QRS wykorzystujący dynamicznie rekonfigurowalną matrycę analogową
Machler A., Pietraszek S., Przybyła T.
Pomiary Automatyka Kontrola
|
2011
|
R. 57, nr 1
22-24
PL
W artykule zaprezentowano nową koncepcję układu detekcji w czasie rzeczywistym zespołu QRS z przebiegu elektrokardiograficzngo. W detektorze wykorzystano programowalną matrycę analogową AN221E04 firmy Anadigm. Parametry wybranych bloków są na bieżąco zmieniane w zależności od zmian parametrów przebiegu EKG dzięki dynamicznej rekonfigurowalności układu. Uzyskano bardzo krótki czas reakcji detektora na wykryty zespół QRS przy zadowalającej skuteczności detekcji. Opracowany detektor może znaleźć zastosowanie w aplikacjach biomedycznych wymagających wykrywania zespołu QRS w przebiegu EKG z małym opóźnieniem czasowym.
EN
In many applications it is important to detect the QRS complex in the ECG waveform with possibly low time delay. Traditional software detectors of the QRS complex implement algorithms, usually based on cascades of digital filters, introduce delays up to parts of a second. Hardware QRS detectors (Fig. 1) fulfill the low delay requirements, but have worse adaptive features for the changing ECG shape. In this paper a new approach to QRS detection is presented. The proposed solution implements a classical detector structure in a Field Programmable Analog Array (FPAA) i.e. AN221E04 circuit from the AnadigmŽ company - Fig. 3. The most interesting feature of the FPAA is the dynamic reconfigurability. This solution makes it possible to modify the parameters of particular blocks of the detector or even the whole structure during runtime, without any changes in hardware and disturbance of the system functionality. Important parameters of particular blocks of the QRS detector are modified on-the-fly according to changes observed in the ECG signal. New data are calculated by the AD7020 microcontroller and downloaded to the FPAA using dynamic reconfigurability after each QRS detection. The prototype QRS detector was tested using a real ECG signal taken from Mit-Bih Arrythmia Database. The results obtained in the prototype circuit (Table 1) show that the detection delay is really small. The error rate of the QRS detection is low and can be acceptable in most real time applications.
16
Content available An approach to unsupervised classification
Przybyła T., Pander T., Horoba K., Kupka T., Matonia A.
Journal of Medical Informatics & Technologies
|
2011
|
Vol. 17
105--111
EN
Classification methods can be divided into supervised and unsupervised methods. The supervised classifier requires a training set for the classifier parameter estimation. In the case of absence of a training set, the popular classifiers (e.g. K-Nearest Neighbors) can not be used. The clustering methods are considered as unsupervised classification methods. This paper presents an idea of the unsupervised classification with the popular classifiers. The fuzzy clustering method is used to create a learning set. The learning set includes only these patterns that are the best representative of each class in the input dataset. The numerical experiment uses an artificial dataset as well as the medical datasets (PIMA, Wisconsin Breast Cancer) and illustrates the usefulness of the proposed method.
17
Content available Improving the periodicity measurement in fetal heart activity signal
Roj D., Wróbel J., Horoba K., Przybyła T., Kupka T.
Journal of Medical Informatics & Technologies
|
2010
|
Vol. 16
19--26
EN
In this paper we discussed the influence of preliminary processing of the ultrasound Doppler signal on accuracy of the fetal heart rate estimation as well as on reliability of the FHR instantaneous variability assessment. We attempted to develop an optimal processing channel of US Doppler signal in order to measure the periodicity of fetal heart activity with accuracy as close as possible to that ensured by FECG. The FHR values determined from the US signal were compared to the reference data obtained from direct FECG. In a final evaluation we used the parameters describing the FHR variability as the clinically important signal features being the most sensitive to any periodicity inaccuracy. The results proved that an application of proposed algorithms improves the accuracy of interval measurements and FHR instantaneous variability assessment in relation to the new-generation fetal monitors.
18
Content available Generalized fuzzy clustering method
Przybyła T., Roj D., Jeżewski J., Matonia A.
Journal of Medical Informatics & Technologies
|
2010
|
Vol. 16
69--76
EN
This paper presents a new hybrid fuzzy clustering method. In the proposed method, cluster prototypes are values that minimize the introduced generalized cost function. The proposed method can be considered as a generalization of fuzzy c–means (FCM) method as well as the fuzzy c–median (FCMed) clustering method. The generalization of the cluster cost function is made by applying the Lp norm. The values that minimize the proposed cost function have been chosen as the group prototypes. The weighted myriad is the special case of the group prototype, when the Lp norm is the L2 (Euclidean) norm. The cluster prototypes are the weighted meridians for the L1 norm. Artificial data set is used to demonstrate the performance of proposed method.
19
Content available remote Zdalne monitorowanie i diagnostyka silników spalinowych z wykorzystaniem technologii OBD II/EOBD
Merkisz J., Pielecha J., Przybyła T., Kamiński T., Sosnowski R.
Silniki Spalinowe
|
2009
|
R. 48, SC1
54--61
PL
W trakcie prac nad systemem zdalnej diagnostyki pojazdów samochodowych wykorzystano techniczne możliwości wprowadzenia do motoryzacji standardu OBD II. W artykule przedstawiono możliwości implementacji systemu diagnostyki pokładowej trzeciej generacji. Zaprojektowano, a następnie stworzono wielomodułowy system pozwalający na dostęp do aktualnych danych bez konieczności fizycznego kontaktu z pojazdem. Uzyskano narzędzie pozwalające na komunikację z siecią pokładową samochodu w standardzie OBD II, a jednocześnie umożliwiające dalszą bezprzewodową transmisję danych. W drugiej części artykułu zaprezentowano możliwości wykorzystania takiego systemu do pomiarów parametrów eksploatacyjnych pojazdów.
EN
The article presents how in the course of work on a remote diagnostic system for motor vehicles technical capabilities enabled by the introduction of the OBD II standard to motor industry were used. The paper reports a third generation diagnostic system, designed and implemented as a multi-module system facilitating acquisition of real-time power-train diagnostic data without wired connection to the vehicle, eventually resulting in creation of a tool accessing the vehicle on-board network using the standard OBD II diagnostic port and an Internet link for simultaneous transmission of diagnostic data to remote operator station. Subsequently, the article covers some practical examples of using the designed system to acquire current, power-train and diagnostic data from the vehicle during its normal operation.
20
Content available Unsupervised clustering for fetal state assessment based on selected features of the cardiotocographic signals
Przybyła T., Jeżewski J., Roj D.
Journal of Medical Informatics & Technologies
|
2009
|
Vol. 13
157--162
EN
In modern obstetrics the cardiotocography is a routine method of fetal condition assessment based mainly on analysis of the fetal heart rate signals. The correct interpretation of recorded traces from a bedside monitor is very difficult even for experienced clinicians. Therefore, computerized fetal monitoring systems are used to yield the quantitative description of the signal. However, the effective techniques enabling automated conclusion generation based on cardiotocograms are still being searched. The paper presents an attempt to diagnose the fetal state basing on seventeen features describing the cardiotocographic records. The proposed method applies the unsupervised classification of signals. During our research we tried to classify the fetal state using the fuzzy c-means (FCM) clustering. We also tested how the efficiency of classification could be influenced by application of principal component analysis (PCA) algorithm. The obtained results showed that unsupervised classification cannot be considered as a support to fetal state assessment.
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