Risk-Adapted Access Control with Multimodal Biometric Identification

The presented article examines the background of biometric identification. As a technical method of authentication, biometrics suffers from some limitations. These limitations are due to human nature, because skin, appearance and behavior changes more or less continuously in time. Changing patterns affect quality and always pose a significantly higher risk. This study investigated risk adaption and the integration of the mathematical representation of this risk into the whole authentication process. Several biometrical identification methods have been compared in order to find an algorithm of a multimodal biometric identification process as a possible solution to simultaneously improve the rates of failed acceptations and rejections. This unique solution is based on the Adaptive Neuro-Fuzzy Inference System and the Bayesian Theorem

Three-dimensional Wentzel-Kramers-Brillouin approach for the simulation of scanning tunneling microscopy and spectroscopy

We review the recently developed three-dimensional (3D) atom-superposition approach for simulating scanning tunneling microscopy (STM) and spectroscopy (STS) based on ab initio electronic structure data. In the method, contributions from individual electron tunneling transitions between the tip apex atom and each of the sample surface atoms are summed up assuming the one-dimensional (1D) Wentzel-Kramers-Brillouin (WKB) approximation in all these transitions. This 3D WKB tunneling model is extremely suitable to simulate spin-polarized STM and STS on surfaces exhibiting a complex noncollinear magnetic structure, i.e., without a global spin quantization axis, at very low computational cost. The tip electronic structure from first principles can also be incorporated into the model, that is often assumed to be constant in energy in the vast majority of the related literature, which could lead to a misinterpretation of experimental findings. Using this approach, we highlight some of the electron tunneling features on a prototype frustrated hexagonal antiferromagnetic Cr monolayer on Ag(111) surface. We obtain useful theoretical insights into the simulated quantities that is expected to help the correct evaluation of experimental results. By extending the method to incorporate a simple orbital dependent electron tunneling transmission, we reinvestigate the bias voltage- and tip-dependent contrast inversion effect on the W(110) surface. STM images calculated using this orbital dependent model agree reasonably well with Tersoff-Hamann and Bardeen results. The computational efficiency of the model is remarkable as the k-point samplings of the surface and tip Brillouin zones do not affect the computational time, in contrast to the Bardeen method. In a certain case we obtain a relative computational time gain of 8500 compared to the Bardeen calculation, without the loss of quality. We discuss the advantages and limitations of the 3D WKB method, and show further ways to improve and extend it

A fuzzy logika alkalmazása a multi-modális biometrikus azonosításban

In this paper we presented an algorithm which can be applied in biometrical identification, especially wherever the high level of false rejection is significant. As the biometrics spreads, the basic difficulties of the controller algorithms are leading us to invent an appropriate technique, which is able to adapt and enough flexible to deal with the daily fluctuations. These daily changes may derive from the routines of the usage, the environmental impacts or even the natural lesions and changes of the user's individual biological identification patterns. The fuzzy logic as a soft computing method applies the artificial intelligence, which based on human thinking and behavior. The fuzzy logic involves the linguistic variables instead of exact numerical equations, and makes implications just like human logic. To highlight the results of our experiments we compared that with the classical mean value calculations

Az emberi észlelésen alapuló mesterséges intelligencia modellezése a személyazonosításban

Nowadays, in the current political and economical environment the identification of the natural persons is a major challenge. The biometrics as a modern branch of science tries to solve these difficulties. For us, in the Applied Biometrics Institute the most difficult task is to generating an operative artificial copy of our biological perceptual system. In this study we examined those soft computing methods which could be applied as an artificial intelligence method for the implementation of the human biological and psychological processes. According to our outlined model, there is a possible way the create operative biometrical identification devices, which are able to implement the cognitive knowledge and to learn like the human beings

A fuzzy logika alkalmazása a multi-modális biometrikus azonosításban

In this paper we presented an algorithm which can be applied in biometrical identification, especially wherever the high level of false rejection is significant. As the biometrics spreads, the basic difficulties of the controller algorithms are leading us to invent an appropriate technique, which is able to adapt and enough flexible to deal with the daily fluctuations. These daily changes may derive from the routines of the usage, the environmental impacts or even the natural lesions and changes of the user's individual biological identification patterns. The fuzzy logic as a soft computing method applies the artificial intelligence, which based on human thinking and behavior. The fuzzy logic involves the linguistic variables instead of exact numerical equations, and makes implications just like human logic. To highlight the results of our experiments we compared that with the classical mean value calculations

Az emberi észlelésen alapuló mesterséges intelligencia modellezése a személyazonosításban

Nowadays, in the current political and economical environment the identification of the natural persons is a major challenge. The biometrics as a modern branch of science tries to solve these difficulties. For us, in the Applied Biometrics Institute the most difficult task is to generating an operative artificial copy of our biological perceptual system. In this study we examined those soft computing methods which could be applied as an artificial intelligence method for the implementation of the human biological and psychological processes. According to our outlined model, there is a possible way the create operative biometrical identification devices, which are able to implement the cognitive knowledge and to learn like the human beings

A mesterséges neurális hálózatok alkalmazásának lehetőségei a biometrikus személyazonosításban

Cikkünkben a mesterséges neurális hálózatok biometriában történő alkalmazhatóságát vizsgáltuk. Bemutattuk, hogy a mesterséges neurális hálók hogyan épülnek fel, mi adja működésük alapját és milyen problémák megoldására alkalmazhatóak. Egy általános, de plasztikus leírással pontról pontra ismertetjük az általunk alkalmazott algoritmus működését, felkeltve az olvasó figyelmét azokra a nehézségekre amiket mi is megtapasztaltunk

POLYETHYLENE GLYCOL DERIVATIVES AND THE PHASE-TRANSFER CATALYSIS

The phase-transfer catalyst efficiency of polyethylene glycols were proven and analysed. The stability of their sodium complexes increases with the length of chain while the lipophilicity decreases. As a result the best phase-transfer catalyst PEO-s can be found among the medium chainlength ones

Nanoszerkezetű amfifil kotérhálók és gélek = Nanostructured Amphiphilic Conetworks and Gels

Nemzetközi együttműködés keretében jól definiált szerkezetű és molekulatömegű blokk-kopolimerek térhálósításával modell kotérhálónak tekinthető anyagokat állítottunk elő, és felderítettük az összetétel, szerkezet és tulajdonságok közötti alapvető összefüggéseket. Kétféle, szupramolekuláris kapcsolódással létrejövő poli(etilén-oxid)-poliizobutilén (PEO-PIB) kotérháló előállítását valósítottuk meg. Hidrogén-hidas kapcsolódással kialakított kotérhálók esetében mágneses vas-oxid nanorészecskék bevitele a kotérhálóba mágneses térre érzékeny termikusan reverzibilis szupramolekuláris gélt eredményezett. A másik esetben PEO-b-PIB blokk-kopolimer képezte egy fizikai térháló és gél kialakulását. Bizonyos körülmények között nanoméretű szférikus micellák képződtek, amelyek kiváló nanotemplátnak bizonyultak nanopórusos szervetlen anyagok (pl. SiO2 és TiO2) létrehozására. | In the framework of international cooperation, model polymer conetworks were synthesized from block copolymers with well-defined structures and molecular weights , and the fundamental relations between composition, structure and properties of the resulting conetworks were investigated and revealed. Two types of poly(ethyleneoxide)-polyisobutylene (PEO-PIB) conetworks were prepared via supramolecular interactions. Incorporation of iron oxide nanoparticles into hydrogen-bonded conetworks resulted in magneto responsive thermally reversible gels. In another approach, PEO-b-PIB block copolymers led to physical networks and gels. Under certain conditions, nanometer sized micelles are formed in these gels, which were utilized as robust nanotemplates for the preparation of nanoporous inorganic materials, such as SiO2 and TiO4