557 research outputs found

    On the number of two-dimensional threshold functions

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    A two-dimensional threshold function of k-valued logic can be viewed as coloring of the points of a k x k square lattice into two colors such that there exists a straight line separating points of different colors. For the number of such functions only asymptotic bounds are known. We give an exact formula for the number of two-dimensional threshold functions and derive more accurate asymptotics.Comment: 17 pages, 2 figure

    Optical models of the molecular atmosphere

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    The use of optical and laser methods for performing atmospheric investigations has stimulated the development of the optical models of the atmosphere. The principles of constructing the optical models of molecular atmosphere for radiation with different spectral composition (wideband, narrowband, and monochromatic) are considered in the case of linear and nonlinear absorptions. The example of the development of a system which provides for the modeling of the processes of optical-wave energy transfer in the atmosphere is presented. Its physical foundations, structure, programming software, and functioning were considered

    On Lidar Sounding of the Atmosphere to Estimate Static and Dynamic Characteristics of Aerosol Inhomogeneities

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    1. A possible application of intensity fluctuations of a pulse light signal reflected by atmospheric aerosols is analyzed by the correlation method to evaluate static (medium sizes, shape) and dynamic (speed and direction of movement, lifetime) characteristics of aerosol inhomogeneities. The aerosol inhomogeneities are assumed to be expanded, pressed, disintegrated and originated constantly in accordance with random laws, the set of inhomogeneities as a whole traveling together with air masses and having predominant movement in wind direction. It is shown that the characteristics of aerosol inhomogeneities considered can be expressed by the coefficients of the correlation function expansion of the reflected signal fluctuation intensity in Tailor series. 2/ Correlation systems for evaluating static and dynamic characteristics of driving objects can be divided into two types according to the kind and quantity of used information: the systems with coordinates of the information removal "points" to be fixed in space, and the systems with a parallel simultaneous information removal at discrete moments of time. The systems for determination of wind direction considered in are the examples of the first type system. However, the operating information removal for two points is insufficient to estimate completely static and dynamic characteristics of inhomogenities, their quantity ought to be increased up to three of them for two-dimensional problem and up to four of them for three-dimensional problem as it is usually done in the ionospheric studies. The second type systems are used for the investigation of a medium shape and speed of the clouds according to photographs made from satellites. These systems are also used for solution of navigation problems. The use of optical quantum generators with a scanning beam is seen to increase greatly the working information removal in comparison with the first type systems. Nevertheless, scanning rate is not sufficient sometimes in order to consider a general picture of aerosol inhomogeneities to be stationary. In this connection the use of the systems of second type treatment becomes a matter of essential difficulty. 3. Aerosol inhomogeneities simulation has been carried out on the basis of the digital computer experiments with the aim of estimating static and dynamic characteristics of inhomogeneities by an optical beam in the atmosphere at different scanning procedures. The dependence of determination accuracy of these characteristics on the type of chosen laws of aerosol particle distribution in the atmosphere, the parameters of inhomogeneities geometry, their speed and the law of scanning have been obtained

    The etiological structure of mass diseases with young gastro and respiratory syndrome

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    Etiology gastroenteritis and pneumonia animals studied complex, on the basis of epizootic, clinical, pathological data, bacteriological results, serology, hematology, immunobiochemical research method

    PrBaCo 2 O 6−δ -Ce 0.8 Sm 0.2 O 1.9 composite cathodes for intermediate-temperature solid oxide fuel cells: Stability and cation interdiffusion

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    The single-phase oxide PrBaCo 2 O 6−δ and composites (100 − y)PrBaCo 2 O 6−δ -yCe 0.8 Sm 0.2 O 1.9 (y = 10–30 wt.%) were investigated as cathode materials for intermediate-temperature solid oxide fuel cells. The chemical compatibility, cation interdiffusion, thermal expansion and dc conductivity were studied. As a result, strong interdiffusion of Pr and Sm was found between PrBaCo 2 O 6−δ and Ce 0.8 Sm 0.2 O 1.9 . This leads to only insignificantly decreasing thermal expansion coefficient of composite with increasing fraction of Ce 0.8 Sm 0.2 O 1.9 and, thus, mixing PrBaCo 2 O 6−δ with Ce 0.8 Sm 0.2 O 1.9 does not improve thermal expansion behavior of the cathode material. Moreover, formation of poorly-conducting BaCeO 3 , caused by chemical interaction between the double perovskite and doped ceria, was shown to lead to pronounced drop in the electrical conductivity of the composite cathode material with increasing Ce 0.8 Sm 0.2 O 1.9 content. © 2019 by the authors

    Laser sounding of instantaneous and mean speed of wind using correlation method

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    The correlation methods for laser sounding of wind speed are based on mutual processing of lidar signals scattered from several spatially separated volumes at each altitude investigated. The time of atmospheric aerosol transport between the scattering volumes estimated by the position of maximum of the mutual correlation function is the measure of corresponding wind speed. In this case the distance between the scattering volumes (the measuring base), defining the time of aerosol movement through the measuring base also determines the lidar possibilities for measuring the instantaneous (during the time interval of several seconds) or the mean wind speed (some minutes). Based on the experimental investigations performed using two lidars, these possibilites are analyzed

    Sources for the breeding of soft spring wheat in the conditions of Novosibirsk region

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    The sources were identified among collection samples characterized by highly pronounced economic and valuable features, which allows new geographically remote source material to be taken to the regional breeding practices. This research aims to assess the agronomic traits (duration of the growing period, lodging resistance and plant height, 1000-grain weight, grain weight and yield) in soft spring wheat varieties of different ecological and geographical origin. Estimation was carried out by a 9-point system of expression of the trait during the study, which allows identifying samples with the greatest expression of the trait in the years of study with respect to the average experience. 5439 samples have been studied over 28 years, with 1106 of them, over two years or more. The study was carried out according to the methods of VIR on plots of 2 m2. It was shown that the samples mainly had no correlation between the yield and the duration of the growing period, while the average dependence (г = 0.6) was revealed between the yield and the height of the plants. Varieties forming the intermediate (4.5-5 points) and above average (6-7) yield in a short growing period (69-85 days) were identified (Lutescens 675, Irkut-skaya 49, Simbirca, Hybrid F3 S-141, Hybrid F4, Hybrid F3 S-289 and Hybrid F4 S-2300 and Pamyati Vavenko-va). A high average score (8.6-9) at 1000 grains weight was shown for 16 varieties with variation from 37 g (N43 and IAO-9) to 56 g (Hofed 1). A high average score (8-9) in the evaluation of grain weight was shown for Pamyati Leont'eva, Ekada 70, Simbirtsit, Don Jose, Yong-Liang 4 and Long-Mai 11, which formed ears with an average weight from 0.96 to 2.30 g. A consistently high score (9) reflecting the yield was in the varieties Condestavel, PF 843025, Prilenskaya 19, Pamyati Leont'eva, Omskaya Krasa

    The distinctive features of plastic deformation localization in polycrystalline aluminum by creep

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    The research was performed for polycrystalline aluminum by steady-state creep. It is known that at the macro-scale level, deformation exhibits localized behavior. The localization patterns would propagate over the deforming sample by steady-state creep, forming thereby a kind of phase autowave. The rate of phase autowave increases with the growing extent of straining. It is demonstrated that the processes controlling the autowave rate have the same activation volume as the processes controlling the creep rate

    Powdery mildew resistance of Nordic spring bread wheat accessions from the collection of the Vavilov Institute (VIR)

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    Background. Powdery mildew is one of the harmful and destructive foliar diseases of cereal crops, caused by the fungus Вlumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal. Annual harvest losses may reach 10–15%, and up to 30% in an epidemic year. The VIR collection contains rich diversity of wheat, a valuable source of original material for wheat resistance breeding programs.The aim of this study was to generalize the results of long-term field and laboratory investigations on powdery mildew resistance in spring bread wheat of Nordic origin from the VIR collection and search for accessions resistant in all development phases.Materials and methods. Powdery mildew resistance was analyzed in 279 accessions originated from Sweden, Finland, Norway and Denmark. The tests were performed from 1961 to 2019 against a natural population of the fungus in VIR’s experimental field (Pushkin, St. Petersburg). Field and laboratory studies were carried out in accordance with the guidelines developed by VIR.Results. The analysis of the field data on powdery mildew resistance in spring bread wheat accessions against the Pushkin population of the fungus showed that many Nordic accessions were resistant from 1970 till 1990. These data were retested in 2012–2013. One hundred and five accessions of old landraces and modern cultivars of Nordic origin were studied under field and laboratory conditions for their response to a natural population of the fungus. Accessions resistant in all phases of plant development were identified.Conclusion. Swedish cultivars ‘Sunnan’ (k-58177), ‘Canon’ (k-60992), ‘Sober’ (k-61080) ‘Dragon’ (k-61515) and ‘Dacke’ (k-63479) preserved their resistance to the powdery mildew population beginning from 1993. Spring bread wheat cultivars ‘SW Vals’ (k-64436), ‘SW Milljet’ (k-64434), ‘SW Estrad’ (k-64435), ‘SW Vinjet’ (k-64436), ‘Zebra’ (k-64707), ‘SW Kungsjet’ (k-66036), ‘SW Kronjet’ (k-66097) and ‘Boett’ (k66353) demonstrated adult and seedling resistance in the period from 2005 to 2019
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