Liveness Detection of a Finger Based on Changes of Papillary Lines

Existuje mnoho spôsobov podvodov proti biometrickým systémom (BS) a niekoľko techník na zabezpečenie BS proti týmto podvodom. Jednou z nich je detekcia živosti. Na oklamanie senzorov otlačkov prstov sa používajú latentné otlačky, gummené napodobeniny prstov a tenké fólie pripevnené k povrchu prstu. Počas skenovania otlačku prstu sa tiež využíva detekcia živosti. Používajú sa rôzne vlastnosti živého prstu, napr. pot, elektrická vodivosť, atď. V tejto diplomovej práci je skúmaný nový prístup k rozpoznávaniu živosti. Je založený na rozťažnosti prstu ako dôsledku úderov srdca/pulzu. Ako sa koža rozťahuje, zväčšujú sa aj vzdialenosti papilárnych línií. Celý prst expanduje približne o 4,5µm, dve susedné papilárne línie o 0,454µm. Táto hodnota koliduje s vlnovou dĺžkou modrého a zeleného svetla. Výsledok práce je nasledovný. Rozlíšenie snímacieho zariadenia nie je dostatočné na zachytenie rozťažnosti medzi dvoma susednými papilárnymi líniami. Taktiež, z dôvodu kolízie s vlnovou dĺžkou viditelného svetla sa prejavuju difrakčný efekt a výsledok je ovplyvnený touto chybou.There are several frauds against biometric systems (BSs) and several techniques exist to secure BSs against these frauds. One of the techniques is liveness detection. To fool fingerprint sensors, latent fingerprints, dummy fingers and wafer-thin layer attached to the finger are being used. Liveness detection is being used also when scanning fingerprints. Several different characteristics of the live finger can be used to detect liveness, for example sweat, conductivity etc. In this thesis, new approach is examined. It is based on the expandability of the finger as an effect of heartbeats/pulsation. As the skin is expanding, also the distances between papillary lines are expanding. Whole finger expands approximately in range of 4,5 ľm , the distance between two neighbor papillary lines in 0,454 ľm . This value collides with wavelength of blue and green light. The result from this work is following. The resolution of the capturing device is not high enough to capture the expandability on distance between two neighbor papillary lines. Also, because of collision with wavelength, the diffraction effect is presented and the result images are influenced by this error.

Identification of Bacterial and Fungal Communities in the Roots of Orchids and Surrounding Soil in Heavy Metal Contaminated Area of Mining Heaps

Orchids represent a unique group of plants that are well adapted to extreme conditions. In our study, we aimed to determine if different soil contamination and pH significantly change fungal and bacterial composition. We identified bacterial and fungal communities from the roots and the surrounding soil of the family Orchidaceae growing on different mining sites in Slovakia. These communities were detected from the samples of Cephalanthera longifolia and Epipactis pontica from Fe deposit Sirk, E. atrorubens from Ni-Co deposit Dobšiná and Pb-Zn deposit Jasenie and Platanthera bifolia by 16S rRNA gene and ITS next-generation sequencing method. A total of 171 species of fungi and 30 species of bacteria were detected from five samples of orchids. In summary, slight differences in pH of the initial soils do not significantly affect the presence of fungi and bacteria and thus the presence of the studied orchids in these localities. Similarly, the toxic elements in the studied localities, do not affect the occurrence of fungi, bacteria, and orchids. Moreover, Cortinarius saturatus, as a dominant fungus, and Candidatus Udaeobacter as a dominant bacterium were present in all soil samples and some root samples. Finally, many of these fungal and bacterial communities have the potential to be used in the bioremediation of the mining areas