1,138 research outputs found

    Number Phi

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    Fibonacci is one of the most famous names in mathematics. This would come as a surprise to Leonardo Pisano, the mathematician we now know by that name. And he might have been equally surprised that he has been immortalised in the famous sequence – 0, 1, 1, 2, 3, 5, 8, 13, ... – rather than for what is considered his far greater mathematical achievement – helping to popularise our modern number system in the Latin-speaking world. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3510

    Number Phi

    Get PDF
    Fibonacci is one of the most famous names in mathematics. This would come as a surprise to Leonardo Pisano, the mathematician we now know by that name. And he might have been equally surprised that he has been immortalised in the famous sequence – 0, 1, 1, 2, 3, 5, 8, 13, ... – rather than for what is considered his far greater mathematical achievement – helping to popularise our modern number system in the Latin-speaking world. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3510

    Synthesis and characterisation of nanocrystalline ZrN PVD coatings on AISI 430 stainless steel

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    The nanocrystalline films of zirconium nitride have been synthesized using ion-plasma vacuum-arc deposition technique in combination with high-frequency discharge (RF) on AISI 430 stainless steel at 150oC. Structure examinations X-ray fluorescent analysis (XRF), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) with microanalysis (EDS), and transmission electron microscopy (TEM), nanoidentation method – were performed to study phase and chemical composition, surface morphology, microstructure and nanohardness of coatings. The developed technology provided low-temperature coatings synthesis, minimized discharge breakdown decreasing formation of macroparticles (MPs) and allowed to deposit ZrN coatings with hardness variation 26.6…31.5 GPa. It was revealed that ZrN single-phase coatings of cubic modification with finecrystalline grains of 20 nm in size were formed

    Performance Evaluation of Distributed Computing Environments with Hadoop and Spark Frameworks

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    Recently, due to rapid development of information and communication technologies, the data are created and consumed in the avalanche way. Distributed computing create preconditions for analyzing and processing such Big Data by distributing the computations among a number of compute nodes. In this work, performance of distributed computing environments on the basis of Hadoop and Spark frameworks is estimated for real and virtual versions of clusters. As a test task, we chose the classic use case of word counting in texts of various sizes. It was found that the running times grow very fast with the dataset size and faster than a power function even. As to the real and virtual versions of cluster implementations, this tendency is the similar for both Hadoop and Spark frameworks. Moreover, speedup values decrease significantly with the growth of dataset size, especially for virtual version of cluster configuration. The problem of growing data generated by IoT and multimodal (visual, sound, tactile, neuro and brain-computing, muscle and eye tracking, etc.) interaction channels is presented. In the context of this problem, the current observations as to the running times and speedup on Hadoop and Spark frameworks in real and virtual cluster configurations can be very useful for the proper scaling-up and efficient job management, especially for machine learning and Deep Learning applications, where Big Data are widely present.Comment: 5 pages, 1 table, 2017 IEEE International Young Scientists Forum on Applied Physics and Engineering (YSF-2017) (Lviv, Ukraine

    Anti-corrosion ceramic coatings on the surface of Nd-Fe-B repelling magnets

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    The results of vacuum-arc deposition of thin ZrO₂coatings to protect the surface of Nd-Fe-B permanent magnets used as repelling devices in orthodontics are presented. The structure, phase composition and mechanical properties of zirconium dioxide films have been investigated by means of SEM, XRD, EDX, XRF and nanoindentation method. It was revealed the formation of polycrystalline ZrO₂ films of monoclinic modification with average grain size 25 nm. The influence of the ZrO₂ coating in terms of its barrier properties for corrosion in quasi-physiological 0.9 NaCl solution has been studied. Electrochemical measurements indicated good barrier properties of the coating on specimens in the physiological solution environment

    Production of a novel biomacromolecule for nanoelectronic devices and artificial retinas utilizing textile wastewater as carbon source: Optimization by Taguchi experimental design

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    In this study, the ability of Haloarcula sp. IRU1 isolated from Urmia lake, Iran, for production of cruxrhodopsin as a biomacromolecule with nanofunction from textile wastewater was evaluated and optimized by Taguchi experimental design. According to Taguchi method, the optimum conditions at which high cruxrhodopsin production could be achieved were observed to be in the presence of textile wastewater at 0.25 (volume/volume), yeast extract at 0.025 (weight/volume) and KH2PO4 at 0.005 (weight/volume). In conclusion, Haloarcula sp. IRU1 is capable of cruxrhodopsin production from textile wastewater in different conditions

    Plant sulfolipid. II. Mutant study and phosphate deficiency

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    Study with SQDG-deficient mutants showed that formation of the sulfonic acid precursor, UDP-sulfoquinovose, in higher plants is considered to be catalyzed by the orthologous plant proteins SQD1. The second required plant enzyme, SQD2, is highly similar to glycosyltransferases and it is proposed that this protein represents sulfolipid synthase. The results of recent works have shown that for the stable activity PS II needs the presence of SQDG and that it participates in PS II recovering through some mechanism dependent on light. Under phosphate-limiting conditions a decrease in the content of one acidic lipid (PG) was accompanied by an increase in the content of the other acidic lipid (SQDG), which resulted in the maintenance of a certain level of total acidic lipids of chloroplast membranes

    Keyed Non-Parametric Hypothesis Tests

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    The recent popularity of machine learning calls for a deeper understanding of AI security. Amongst the numerous AI threats published so far, poisoning attacks currently attract considerable attention. In a poisoning attack the opponent partially tampers the dataset used for learning to mislead the classifier during the testing phase. This paper proposes a new protection strategy against poisoning attacks. The technique relies on a new primitive called keyed non-parametric hypothesis tests allowing to evaluate under adversarial conditions the training input's conformance with a previously learned distribution D\mathfrak{D}. To do so we use a secret key κ\kappa unknown to the opponent. Keyed non-parametric hypothesis tests differs from classical tests in that the secrecy of κ\kappa prevents the opponent from misleading the keyed test into concluding that a (significantly) tampered dataset belongs to D\mathfrak{D}.Comment: Paper published in NSS 201

    Expermental research of the effects of benofilin on the functional renal function in the evalution of ethylene glycol toxic loss

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    Effect of benofilin – a new compound among a new derivative of theophylline and hofitol (70 mg/kg) on functional renal function was studied based on the rat experimental model of acute kidney damage by ethylene glycol. The toxic products of the metabolism of ethylene glycol cause renal tubular damage resulting in acute renal failure (ARF). As a result of the application of benofilin its ability is established to prevent the death of animals in the first day of the experiment. By the ability to prevent impaired kidney function in rats benofilin exceeds the effect of the hofitol
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