85 research outputs found

    Asymptotically false-positive-maximizing attack on non-binary Tardos codes

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    We use a method recently introduced by Simone and Skoric to study accusation probabilities for non-binary Tardos fingerprinting codes. We generalize the pre-computation steps in this approach to include a broad class of collusion attack strategies. We analytically derive properties of a special attack that asymptotically maximizes false accusation probabilities. We present numerical results on sufficient code lengths for this attack, and explain the abrupt transitions that occur in these results

    Karakterizacija dupleks tvrdih prevlaka sa dodatnom ionskom primjenom

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    In this paper, we present the results of a study of TiN thin films which are deposited by a Physical Vapour Deposition (PVD) and Ion Beam Assisted Deposition (IBAD). In the present investigation the subsequent ion implantation was provided with N+2 ions. The ion implantation was applied to enhance the mechanical properties of surface. The thin film deposition process exerts a number of effects such as crystallographic orientation, morphology, topography, densification of the films. The evolution of the microstructure from porous and columnar grains to densel packed grains is accompanied by changes in mechanical and physical properties. A variety of analytic techniques were used for characterization, such as scratch test, calo test, Scanning electron microscopy (SEM), Atomic Force Microscope (AFM), X-ray diffraction (XRD) and Energy Dispersive X-ray analysis (EDAX).U ovom radu pretstavljaju se rezultati istraživanja TiN tankih fi lmova, nanešenih fi zičkim odlaganjem iz parne faze i te podržani ionskim snopom. U ovom istraživanju je izvršena i naknadna ionska primjena sa N+2 ionima. Ionska primjena je sprovedena radi poboljšanja mehaničkih svojstava površina. Proces nanošenja tankih fi lmova karakterizira veliki broj učinaka, kao što su: kristalografska orijentacija, morfologija, topografi ja, gustoća fi lma. Razvoj mikrostrukture od porozne i stubaste u zrnastu gusto pakovanu, se dešava uz istovremenu promjenu mehaničkih i fi zičkih svojstava. Za karakterizaciju su rabljene različite analitičke tehnike, kao što su test zaparavanja, kalo test, skenirajući elektronski mikroskop (SEM), mikroskop atomskih sila (AFM), rentgenska difrakcija X zraka (XRD) i energijska disperzivna analiza X zraka (EDAX)

    Characterization of duplex hard coatings with additional ion implantation

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    In this paper, we present the results of a study of TiN thin fi lms which are deposited by a Physical Vapour Deposition (PVD) and Ion Beam Assisted Deposition (IBAD). In the present investigation the subsequent ion implantation was provided with N<sup>+2</sup> ions. The ion implantation was applied to enhance the mechanical properties of surface. The thin film deposition process exerts a number of eff ects such as crystallographic orientation, morphology, topography, densifi cation of the fi lms. The evolution of the microstructure from porous and columnar grains to densel packed grains is accompanied by changes in mechanical and physical properties. A variety of analytic techniques were used for characterization, such as scratch test, calo test, Scanning electron microscopy (SEM), Atomic Force Microscope (AFM), X-ray diff raction (XRD) and Energy Dispersive X-ray analysis (EDAX)

    Stanje površinskog sloja materijala obratka kod visokoučinskog brušenja

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    This paper focuses on the development of high temperatures in the cutting zone during high performance grinding. In order to identify the influence of grinding temperature on surface integrity, temperatures were measured in the workpiece surface layer under different machining conditions. Beside this, under the same conditions, the surface layer properties of the workpiece material were determined through metallographic examination. Microstructureand microhardness of the workpiece surface layer, as well as the burned surfaces and microcracks phenomena were investigated. The conducted experimental investigations allow the surface layer properties of the workpiece material in high performance grinding to be defined.U članku se ukazuje na pojavu visokih temperatura u zoni rezanja pri visokoučinskom brušenju. Da bi se ustanovio utjecaj temperature brušenja na kvalitet obrađene površine, izmjerene su temperature u površinskom sloju materijala obratka pri različitim uvjetima obrade. Ujedno je pri istim uvjetima obrade određeno stanje površinskog sloja materijala obratka metalografskim ispitivanjima. Ispitane su mikrostruktura i mikrotvrdoća površinskog sloja obratka i pojava nagorjelih površina i mikropukotina. Izvedena eksperimentalna istraživanja defi niraju stanje površinskog sloja materijala obratka kod visokoučinskog brušenja

    On entropy of probability integral transformed time series

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    Abstract The goal of this paper is to investigate the changes of entropy estimates when the amplitude distribution of the time series is equalized using the probability integral transformation. The data we analyzed were with known properties—pseudo-random signals with known distributions, mutually coupled using statistical or deterministic methods that include generators of statistically dependent distributions, linear and non-linear transforms, and deterministic chaos. The signal pairs were coupled using a correlation coefficient ranging from zero to one. The dependence of the signal samples is achieved by moving average filter and non-linear equations. The applied coupling methods are checked using statistical tests for correlation. The changes in signal regularity are checked by a multifractal spectrum. The probability integral transformation is then applied to cardiovascular time series—systolic blood pressure and pulse interval—acquired from the laboratory animals and represented the results of entropy estimations. We derived an expression for the reference value of entropy in the probability integral transformed signals. We also experimentally evaluated the reliability of entropy estimates concerning the matching probabilities

    Effect of water stress on yield and evapotranspiration of sunflower

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    An experiment was conducted at Rimski Šančevi Experiment Field of Institute of Field and Vegetable Crops in Novi Sad during 2000 - 2005. The soil in the experimental plot was calcareous chernozem on loess terrace. Using the yield response factor (ky), the study investigated how sunflower yield and evapotranspiration were affected by deficit of available soil water during the growing season. The experiment consisted of an irrigated treatment (T1), in which irrigation was used when soil moisture levels dropped to 60-65% of FC (field capacity), and a nonirrigated control treatment (T0). The sunflower hybrid used in the study was NS-H-111. On average, no significant differences in yield level were observed between T1 (3.79 t ha-1) and T0 (3.75 t ha-1) treatments. Seasonal evapotranspiration (ETm) obtained in T1 treatment was in the 402-479 mm range. The yield response factor (ky) was obtained as 0.20 for total growing season and 0.27, 0.31 and 0.48 for vegetative, flowering and yield formation period, respectively. Period from flowering to maturity was the most sensitive towards water deficiency

    The wild sunflowers collection in Novi Sad

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    Lowered genetic variability in the cultivated sunflower and use of interspecies hybridization in sunflower breeding were the main reasons to establish the wild species collection. Wild species were collected during collecting trips performed jointly by researchers from Novi Sad and Fargo from 1980 to 1991. A total of 917 accessions were gathered. Different numbers of species (1-37) and populations (52-384) were gathered in each trip and wild sunflower habitats were inspected in 6-21 US federal states. Presently there are 21 perennial and 7 annual species in the collection, represented by 447 accessions. The perennial species are grown in quarantine fields (311 accessions) and kept in temporary seed storage at +4° (163 accessions). Annual species are sawn each year and 136 accessions are kept in temporary seed storage. Seed reserves vary from a few seeds to several thousand per accession and all of them were produced in the period between 1998 and 2004. Several problems were encountered in the course of the establishment maintenance and utilization of the collection: 1. Occasional errors in species determination during collection trips were caused by the presence of natural hybrids, heterogeneity of natural populations and differences in ploidy within the same species; 2. The local continental climate caused loss in material due to winterkill and inability of some species to complete the vegetative cycle; 3. Perennial species were difficult to grow because of low seed viability; 4. Low self-fertility or complete selfsterility precluded seed production and renewal of seed reserves; 5. Wild species were difficult to utilize as a source of desirable genes because of their cross incompatibility with cultivated sunflower. The collection of wild sunflower species has mostly been used for development of disease resistant or tolerant genotypes, new cms and Rf genes and for breeding of special-purpose hybrids

    Molecular identification of a phytoplasma infecting grapevine in the Republic of Macedonia

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    Phytoplasmas from the ribosomal subgroup 16SrXII-A (stolbur) were identified by PCR and RFLP analyses of 16S rRNA gene and elongation factor-Tu phytoplasma gene (tuf) in symptomatic grapevines from the Veles and Skopje areas in Macedonia. Two methods were used for nucleic acid extraction. Amplification and RFLP results of 16S rDNA were not influenced by the method used, but RFLP patterns of tuf gene revealed additional bands if a less time consuming method was applied. The possible origin of these bands is discussed. This is the first report of the presence of the stolbur phytoplasma in cvs Chardonnay and Vranac in Macedonia.

    Radiosensitivity of sunflower inbred lines to mutagenesis

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    For much of the past century, mutagenesis has gained popularity in plant genetics research as a means of inducing novel genetic variation. Induced mutations have been applied for the past 40 years to produce mutant cultivars in sunflower by changing plant characteristics that significantly increase plant yield and quality. The present study is focused on generating baseline data to elucidate the role of genotypic differences in the response of sunflower to induced mutagenesis with the aim of expanding the applicability of the use of induced mutant stocks in the genetic improvement of the crop and in its functional genomics. The strategy adopted was to estimate the optimal treatment conditions (doses of mutagens) through relating the extent of damage in seedling progeny to the exposure levels of the initiating propagates to mutagens. Seeds of fifteen elite sunflower genotypes of commonly used as breeding stocks and grown on commercial scales were treated with a range of mutagens: gamma rays (γ rays); fast neutrons and with ethyl-methane-sulphonate (EMS) at different treatment doses. The three mutagenic agents affected seedling height, reducing it with increasing dosage. Based on the mutagen damage on seedling height, the 50% and 30% damage indices (D50 and D30, respectively) were estimated for the 15 sunflower genotypes for the three mutagens. The D50 (D30) values for the sunflower lines ranged from 120 to 325 Gy (5 to 207 Gy) for gamma irradiation; 9 to 21 Gy (0.1 to 10 Gy) for fast neutrons and 0.69 to 1.55% (0.01 to 0.68%) concentration of EMS
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