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1

An accurate fingerprint reference point determination method based on curvature estimation of separated ridges

Doroz R., Wrobel K., Porwik P.

International Journal of Applied Mathematics and Computer Science

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2018

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Vol. 28, no. 1

209--225

EN

This paper presents an effective method for the detection of a fingerprint’s reference point by analyzing fingerprint ridges’ curvatures. The proposed approach is a multi-stage system. The first step extracts the fingerprint ridges from an image and transforms them into chains of discrete points. In the second step, the obtained chains of points are processed by a dedicated algorithm to detect corners and other points of highest curvature on their planar surface. In a series of experiments we demonstrate that the proposed method based on this algorithm allows effective determination of fingerprint reference points. Furthermore, the proposed method is relatively simple and achieves better results when compared with the approaches known from the literature. The reference point detection experiments were conducted using publicly available fingerprint databases FVC2000, FVC2002, FVC2004 and NIST.

2

Hybrid verification method based on finger-knuckle analysis and keystroke dynamics

Wesolowski T. E., Safaverdi H., Doroz R., Wrobel K.

Journal of Medical Informatics & Technologies

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2017

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Vol. 26

26--36

EN

The increasing number of personal data leaks becomes one of the most important security issues hence the need to develop modern computer user verification methods. In the article, a potential of biometric methods fusion for continuous user verification was assessed. A hybrid approach for user verification based on fusion of keystroke dynamics and knuckle images analysis was presented. Verification is performed by a classification module where an ensemble classifier was used to verify the identity of a user. A proposed classifier works on a database which comprises of knuckle images and keyboard events for keystroke dynamics. The proposed approach was tested experimentally. The obtained results confirm that the proposed hybrid approach performs better than methods based on single biometric feature hence the introduced method can be used for increasing a protection level of computer resources against forgers and impostors. The paper presents results of preliminary research conducted to assess the potential of biometric methods fusion.

3

Recognition of lip prints using Fuzzy c-Means clustering

Wrobel K., Froelich W.

Journal of Medical Informatics & Technologies

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2015

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Vol. 24

67--73

EN

In this paper a new method for lip print recognition is proposed. The proposed approach is based on Fuzzy c-Means clustering of the characteristics features of lip prints. First, the Hough transform is applied for the recognition of the characteristic features within lip prints, then Fuzzy c-Means clustering is performed to cluster those features. The proposed algorithm applies the results of clustering to find an unknown image withing the collected repository of lip prints. Instead of comparing all pairs of individual characteristic features, the proposed algorithm uses the representatives of clusters for the comparison of images. The advantage of using the proposed method is its increased tolerance to the noise in data and thus the increased efficiency of the recognition. The effectiveness of presented method has been verified experimentally using real-world images. The results are satisfactory and suggest the possibility of using the method in forensic identification systems

4

Personal identity verification method based on lips photographs

Wrobel K., Doroz R., Porwik P., Naruniec J., Kowalski M.

Journal of Medical Informatics & Technologies

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2015

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Vol. 24

59--65

EN

The paper presents a personal identification method based on lips photographs. This method uses a new approach to the extraction and classification of characteristic features of the mouth from photographs. It eliminates the drawbacks that occur during the acquisition of lip print images with the use of the forensic method that requires special tools. Geometrical dimensions of the entire mouth as well as of the upper and lower lips were adopted as the features, on the basis of which the verification is performed. An ensemble classifier was used for the classification of the features obtained. The effectiveness of the classifier has been verified experimentally.

5

Medical diagnosis using fuzzy cognitive map classifier

Froelich W., Wrobel K.

Journal of Medical Informatics & Technologies

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2015

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Vol. 24

247--254

EN

In this study, we address the problem of medical diagnosis by applying Fuzzy Cognitive Map (FCM). A distinctive feature of the FCM is its ability to simulate the development of the disease in time. By this simulation, it is possible to predict the severity of the disease by having future knowledge on current medical investigations. For the first time in this paper, we construct an FCM-based classifier dedicated solely to perform medical diagnosis. To learn the FCM, we use an evolutionary algorithm explicitly specifying the newly designed fitness function. Real, publicly available medical data are applied for the validation and evaluation of the proposed approach.

6

Method for identification of fragments of lip prints images on the basis of the generalized hough transform

Wrobel K., Doroz R.

Journal of Medical Informatics & Technologies

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2013

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Vol. 22

189--193

EN

The paper presents a new method for identification of fragments of lip print images on the basis of the Generalized Hough Transform (GHT). The effectiveness of this method was verified in practice. The maximum value obtained from the accumulator array after the Hough transform has been assumed as the measure of similarity between a lip print image and a reference object. The advantage of this method is the possibility of use in forensic science to identify persons who left lip prints at crime scenes.

7

Spectrophotometric micro assay for determination of 2-furaldehyde in transformer oils

Rodriguez D. M., Wrobel K., Wrobel K.

Chemia Analityczna

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2005

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Vol. 50, No. 1

315-326

EN

In this work, a spectrophotomelric micro assay has been proposed for the determination of 2-furaIdehyde (2-PAL) in transformer oil. This compound is a degradation product of cellulose-based Kraft paper, which is used for insulation of transformer conductive elements. 2-FAI, has been accepted as the primary chemical indicator o f paper degradation and its determination is necessary in controlling the actual condition of transformer in use. For spectrophotometric measurements, a pink-colored /T-charge transfer complex of 2-FAL with aniline acetate was formed (ε = 23500 L mol-1>cm-1>). The original idea was to enhance overall sensitivity (including preconcentration step) of the previously reported procedures by means of the complex extraction to glacial acetic acid. A micro scale analysis was proposed to reduce the sample volume (1 mL) and to lower the amount of reagents and solvents required (100 μL of aniline, 5% in chloroform and 200 μ of glacial acetic acid). To reduce the effect of sample turbidity, analytical signal was defined as the difference between the absorbances measured at 519 nm (maximum of the complex absorption band) and 594 nm (beyond the spectral band of complex). Within the calibration range 0.1-1.0 mg L-1 R2 value was 0.997. The quantification limit was 34 μg L -1;R2relative standard deviations at two levels of 2-FAL concentration (0.4 and 0.8 mg L-1) respectively 9.8% and 5.5%: and the recovery obtained in the analysis of fortified sample (0.4 mg L-1) was 95š6%. Analytical results of the proposed procedure were compared with those obtained by high perfor mance liquid chromatography with pre-column derivatization (2,4-dinitrophenylhydrazine). In this case, the following aldehydes were also included: 5-hydroxymelhyl-2-furaldehyde, formaldehyde, acetaldehydc, benzaldehyde and 5-methyl-2-furaldehyde, as the possible degradation products of insulation elements (paper and mineral oil).

PL

W niniejszej pracy przedstawiono dwie procedury oznaczania 2-furaIdehydu (2—FAL) w oleju transformatorowym. Wymieniony związek jest produktem rozkładu papieru Krafta, który jest stosowany do izolacji zwojów transformatora. 2-FALjest szeroko stosowany jako chemiczny wskaźnik stopnia zużycia papieru izolującego i oznaczanie jego zawartości w oleju transformatorowym jest elementem kontroli pracującego transformatora. W procedurze wykorzystano opisane w literaturze powstawanie barwnego kompleksu z octanem aniliny ((ε=23500 L -1>cm-1>) Oryginalną ideą było zastosowanie ekstrakcji kompleksu do fazy lodowatego kwasu octowego, co pozwoliło zwiększyć czułość całej procedur) w porównaniu z wcześniejszymi doniesieniami literaturowymi. Zastosowanie mikro skali pozwoliło na użycie niewielkiej ilości próbki (1 m L) i odczynników (1OO μL 5% aniliny w chloroformie i 200 μL lodowatego kwasu octowego) a także wytwarzanych odpadów. W celu zmniejszenia wpływu zmętnienia próbki, sygnał analityczny zdefiniowano jako różnicę absorbancji mierzonych przy 519 nm {maksimum pasma absorpcji kompleksu) i 594 nm (poza pasmem absorpcji). Kalibrację wykonano w zakresie stężeń 2-FAL 0.1-1.0 mg L-1, uzyskując wartość współczynnika korelacji liniowej 0.997. Wartość wyznaczonej granicy oznaczalności wynosiła 34 μg L-1; względnych odchyleń standardowych dla dwóch poziomów stężenia analitu (0.4 and 0.8 rng L-1-1