19 research outputs found

    Secure Biometric Verification Station Based on Iris Recognition, Journal of Telecommunications and Information Technology, 2012, nr 3

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    This paper describes an application of the Zak-Gabor-based iris coding to build a secure biometric verification station (SBS), consisting of a professional iris capture camera, a processing unit with specially designed iris recognition and communication software, as well as a display (LCD). Specially designed protocol controls the access to the station and secures the communication between the station and the external world. Reliability of the Zak-Gabor-based coding, similarly to other wavelet-based methods, strongly depends on appropriate choice of the wavelets employed in image coding. This choice cannot be arbitrary and should be adequate to the employed iris image quality. Thus in this paper we propose an automatic iris feature selection mechanism employing, among others, the minimum redundancy, maximum relevance (mRMR) methodology as one, yet important, step to assess the optimal set of wavelets used in this iris recognition application. System reliability is assessed with approximately 1000 iris images collected by the station for 50 different eyes

    New Class of Antimicrobial Agents: SBA-15 Silica Containing Anchored Copper Ions

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    The paper is about a new class of antimicrobial functional nanomaterials. Proposed compounds are based on SBA-15 porous silica matrices and contain anchored copper ions. Thanks to the immobilization of functional groups the compounds are safer for environment than commonly used disinfectant agents. We prepared and examined silica based materials containing two concentrations of copper-containing groups: 10 and 5%. For the reference we prepared samples containing free-standing CuO molecules in the structure and checked their antimicrobial properties. Antibacterial effect of considered SBA-15-Cu material was tested on Escherichia coli bacteria. Antimicrobial tests were applied for the pure form of the material and as modifying agents for plastics. The obtained results showed that the sample with lower concentration of active copper-containing groups has stronger antimicrobial properties than the one with higher concentration of copper. Interestingly, silica containing free-standing CuO molecules has no antimicrobial properties. Considering the obtained results, we can conclude that the most probable antimicrobial mechanism in this case is an oxidation stress. When a plastic modifier is applied the material is enriched with bacterial inhibitory properties. It seems that SBA-15 silica containing low concentration of anchored copper ions is promising in terms of its antibacterial property and biomaterial potential for commercial use

    Dissolved organic carbon and biodegradable dissolved organic carbon determination in river water of the Strug Basin

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    The aim of the study was to determine Dissolved Organic Carbon (DOC) and Biodegradable Dissolved Organic Carbon (BDOC) concentrations, as well as the correlation between them, in the river water of the Strug basin located in the Carpathian Foothills. The Strug river's hydrographic basin was chosen for the study as it is a typical catchment area, which allows ease of measurement. DOC concentrations in the streams (tributaries) and the Strug ranged from 2.71 to 4.88 mgC/dm3 and from 3.62 to 4.19 mgC/dm3, respectively. BDOC concentrations in the streams and the Strug ranged from 0.40 to 1.09 mgC/dm3 and from 0.64 to 0.77 mgC/dm3, respectively. BDOC, expressed as the percentage of DOC (%BDOC) ranged from 14.76 to 24.78% in the streams, and from 17.68 to 20.11% in the Strug. The procentage of BDOC is independent of DOC concentrations. The season of the year and the size of the watercourse had the greatest impact on DOC and BDOC concentrations

    Knowledge Tracing with Sequential Key-Value Memory Networks

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    Can machines trace human knowledge like humans? Knowledge tracing (KT) is a fundamental task in a wide range of applications in education, such as massive open online courses (MOOCs), intelligent tutoring systems, educational games, and learning management systems. It models dynamics in a student's knowledge states in relation to different learning concepts through their interactions with learning activities. Recently, several attempts have been made to use deep learning models for tackling the KT problem. Although these deep learning models have shown promising results, they have limitations: either lack the ability to go deeper to trace how specific concepts in a knowledge state are mastered by a student, or fail to capture long-term dependencies in an exercise sequence. In this paper, we address these limitations by proposing a novel deep learning model for knowledge tracing, namely Sequential Key-Value Memory Networks (SKVMN). This model unifies the strengths of recurrent modelling capacity and memory capacity of the existing deep learning KT models for modelling student learning. We have extensively evaluated our proposed model on five benchmark datasets. The experimental results show that (1) SKVMN outperforms the state-of-the-art KT models on all datasets, (2) SKVMN can better discover the correlation between latent concepts and questions, and (3) SKVMN can trace the knowledge state of students dynamics, and a leverage sequential dependencies in an exercise sequence for improved predication accuracy

    Mechanistic aspects of the oxidative and reductive fragmentation of n-nitrosoamines: a new method for generating nitrenium cations, amide anions, and aminyl radicals

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    A new method for investigating the mechanisms of nitric oxide release from NO donors under oxidative and reductive conditions is presented. Based on the fragmentation of N-nitrosoamines, it allows generation and spectroscopic characterization of nitrenium cations, amide anions, and aminyl radicals. X-irradiation of N-nitroso-N,N-diphenylamine 1 in Ar matrices at 10 K is found to yield the corresponding radical ions, which apparently undergo spontaneous loss of NO° under the conditions of this experiment (1°⁺ seems to survive partially intact, but not 1°⁻). One-electron reduction or oxidation of 1 is observed upon doping of the Ar matrix with DABCO, an efficient hole scavenger, or CH₂Cl₂, an electron scavenger, respectively. The resulting diphenylnitrenium cation, 2⁺, and the diphenylamide anion, 2⁻, were characterized by their full UV-vis and mid-IR spectra. The best spectra of 2⁺ and 2⁻ were obtained if 1 was homolytically photodissociated to diphenylaminyl radical 2° and NO° prior to ionization. 2⁺ and 2⁻ are bleached on irradiation at 2° or, in part, 1. DFT and CCSD quantum chemical calculations predict that the dissociation of 1°⁺ and 1°⁻ is slightly endothermic, a tendency which is partially reversed if one allows for complexation of the resulting 2⁺ (and, presumably, 2⁻) with NO°. The method described in this work should prove generally applicable to the generation and study of nitrenium cations and amide anions R₂N+/- under matrix and ambient conditions (i.e., in solution)

    Modelowanie 3D z wykorzystaniem metod fotogrametrycznych

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    Extremely intensive development of technology has resulted in many innovations. There are new methods of acquiring spatial data, such as laser scanning, unmanned aerial vehicles or digital non-metric cameras, which are the subject of this study. Integration of this data has become a new tool that has expanded existing measurement capabilities, finding applications in 3D modelling, archaeology and monument conservation. Owing to scanning, we can get the coordinates of almost every point of the scanned surface, obtaining full and detailed information about the object dimensions. The level of technical advancement of digital cameras allows them to be successfully used in short-range photogrammetry [27], and recently also in low-altitude aerial photogrammetry (unmanned aerial vehicles). Two different test objects were selected to achieve the intended purpose. The monument located on the 14-meter-high top of the Wanda Mound was adopted as the first object. It consists of a simple rectangular plinth made of brown marble. On its top there is a figure of an eagle with a crown of white marble. On the west wall of the plinth there is an inscription “Wanda” and a drawing showing a sword crossed with a distaff. The following features supported the choice of the monument: interesting shape of the object, which includes both simple geometric forms with large and flat surfaces (plinth), and more detailed surfaces (figure of an eagle); detailed texture of the object (complicated marble veins, wing details). The second object under study was The Helena Modrzejewska National Stary Theatre. The building was rebuilt in the style of Viennese Art Nouveau, so that it fully incorporates into the rest of buildings. Measurements included data obtained from a non-metric camera, Leica ScanStation scanner and DJI S 1000 multi-rotor.Niezwykle intensywny rozwój technologii od początku obecnego stulecia, zaowocował wieloma innowacjami, również w dziedzinie geodezji i kartografii, a w szczególności w zakresie fotogrametrii i teledetekcji. Oprócz ewolucji znanych już form pomiarów jak przejście ze zobrazowań analogowych na cyfrowe, pojawiły się też nowe metody pozyskiwania danych przestrzennych jak skaning laserowy, bezzałogowe statki powietrzne czy cyfrowe kamery niemetryczne, będące przedmiotem niniejszego opracowania. Integracja tych danych stała się nowym narzędziem, które rozszerzyło dotychczasowe możliwości pomiarowe, jak również znalazło zastosowanie poza branżą geodezyjną, na przykład w modelowaniu 3D, archeologii czy konserwacji zabytków. Dzięki skaningowi otrzymujemy współrzędne niemal każdego punktu skanowanej powierzchni w dowolnym miejscu, nawet już po zakończeniu pomiaru i opuszczeniu obiektu. Otrzymujemy zatem pełną i szczegółową informację o wymiarach obiektu, o znajdującej się wewnątrz infrastrukturze niekiedy trudno dostępnej bądź skomplikowanej. Poziom zaawansowania technicznego aparatów cyfrowych pozwala już od kilkunastu lat na stosowanie ich z powodzeniem w fotogrametrii bliskiego zasięgu [27], a od niedawna także i w fotogrametrii lotniczej niskiego pułapu (bezzałogowe statki powietrzne). Bezzałogowe statki powietrzne okazują się świetnym narzędziem wspomagającym proces zbierania danych o wysokorozdzielczych metrycznych zdjęciach elewacji budynków. Do zrealizowania zamierzonego celu wybrano 2 różne obiekty testowe

    Agricultural utilisation of municipal sludge in willow plantation

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    This paper presents the results of analyses of the monitoring selected energetic willow plantations (30 ha) located in Podkarpackie Province (Poland), which have been fertilised using a prototype trailer for land-applying municipal sludge. The fertilisation of the willow plantation is undertaken using this prototype for the subsurface application of municipal sewage sludge into soil. The presented prototype is a component of technology of energetic plant production that has been developed at the Rzeszow University of Technology. The results of soil investigations allow to us conclude that the deposition of sewage sludge using the presented prototype of the agricultural trailer is conducted in accordance with legal regulations and does not cause significant perturbation of the natural trophic chain

    LTE/GNSS IOT technology as a backbone for airport ground handling operations

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    The necessity of a positioning service for various ground handling assets is key to improving airport performance. Reported in this article is a system named “Ground Eye”, designed to be a test of a possible implementation of the independent LTE-based communication system and GNSS-based location services. The test campaign used a total of nine prototype devices for a period of one month at Gdańsk airport (Poland). The main goal of this demonstration was to verify the possibility of using the GNSS/LTE system as a fast-deployment option in the airport environment, as well as to evaluate its positioning and communication capabilities in conjunction with React.JS/Deck.GL/Node.JS dedicated application. The test campaign verified that even with simple processing and relatively simple single-frequency measurements, multi-constellation GNSS receivers, it is possible to obtain location with precision reaching better than 2.5 metres. This precision should be good enough for all ground handling operations at modern airports, without the need for additional fixed infrastructure

    Dissolved Organic Carbon and Biodegradable Dissolved Organic Carbon determination in river water of the Strug basin

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    The aim of the study was to determine Dissolved Organic Carbon (DOC) and Biodegradable Dissolved Organic Carbon (BDOC) concentrations, as well as the correlation between them, in the river water of the Strug basin located in the Carpathian Foothills. The Strug river's hydrographic basin was chosen for the study as it is a typical catchment area, which allows ease of measurement. DOC concentrations in the streams (tributaries) and the Strug ranged from 2.71 to 4.88 mgC/dm3 and from 3.62 to 4.19 mgC/dm3 , respectively. BDOC concentrations in the streams and the Strug ranged from 0.40 to 1.09 mgC/dm3 and from 0.64 to 0.77 mgC/dm3 , respectively. BDOC, expressed as the percentage of DOC (%BDOC) ranged from 14.76 to 24.78% in the streams, and from 17.68 to 20.11% in the Strug. The procentage of BDOC is independent of DOC concentrations. The season of the year and the size of the watercourse had the greatest impact on DOC and BDOC concentrations

    The Influence of <i>Urtica dioica</i> and <i>Vitis vinifera</i> Fibers on the Thermal Properties and Flammability of Polylactide Composites

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    This study focuses on examining the influence of bast fibers on the flammability and thermal properties of the polylactide matrix (PLA). For this purpose, Urtica dioica and Vitis vinifera fibers were subjected to two types of modifications: mercerization in NaOH solution (M1 route) and encapsulation in an organic PLA solution (M2 route). In a further step, PLA composites containing 5, 10, and 15 wt% of unmodified and chemically treated fibers were obtained. The results of the tests show that only biocomposites containing mercerized fibers had a nearly 20% reduced flammability compared to that of PLA. Moreover, the biofiller obtained in this way belongs to the group of flame retardants that generate char residue during combustion, which was also confirmed by TGA tests. The M2 modification route allowed to achieve higher mass viscosity than the addition of unmodified and M1-modified fibers. The reason is that fibers additionally encapsulated in a polymer layer impede the mobility of the chain segments. The inferior homogenization of the M2-modified fibers in the PLA matrix translated into a longer combustion time and only a 15% reduction in flammability
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