111 research outputs found
Directional Anisotropy of Swift Gamma-Ray Bursts
Swift satellite measurements contributed substantially to the gamma-ray burst
(GRB) redshift observations through fast slewing to the source of the GRBs.
Still, a large number of bursts are without redshift. We study the celestial
distribution of bursts with various methods and compare them to a random
catalog using Monte-Carlo simulations. We find an anisotropy in the
distribution of the intermediate class of bursts and find that the short and
long population are distributed isotropically.Comment: 3 pages, 2 figures, appeared in The Ancient Universe With Gamma-Ray
Bursts. AIP Conference Proceedings, Volume 1279, pp. 457-459 (2010
CD-independent subsets in meet-distributive lattices
A subset of a finite lattice is CD-independent if the meet of any two
incomparable elements of equals 0. In 2009, Cz\'edli, Hartmann and Schmidt
proved that any two maximal CD-independent subsets of a finite distributive
lattice have the same number of elements. In this paper, we prove that if
is a finite meet-distributive lattice, then the size of every CD-independent
subset of is at most the number of atoms of plus the length of . If,
in addition, there is no three-element antichain of meet-irreducible elements,
then we give a recursive description of maximal CD-independent subsets.
Finally, to give an application of CD-independent subsets, we give a new
approach to count islands on a rectangular board.Comment: 14 pages, 4 figure
Large scale smart meter data assessment for energy benchmarking and occupant behaviour profile development
This paper will present objectives and first results of the research project entitled âLarge Scale Smart Meter Data Assessment for Energy Benchmarking and Occupant Behaviour Profile Development of Building Clusters,â implemented in the geographical scope of Hungary. The project seeks to utilize a new and unique opportunity for accessing and processing an enormous dataset collected by smart meters. Recently in Hungary, nearly 10 000 buildings have been equipped with smart meters within the âCentral Smart Grid Pilot Projectâ. By means of advanced data analysis techniques, consumption trends and motivations of building users are being investigated. The aims are to help building designers and engineers design more energy efficient buildings at lower investment costs by avoiding system oversizing, and to obtain better knowledge about hourly, daily and monthly energy consumption trends. Furthermore, standard net demand values for normative energy calculations can be updated and specified more precisely since consumption habits change with time and depend on the region
Multi-modal interfaces for humanârobot communication in collaborative assembly
NicolÄescu-PlopĆor Constantin S., Zaharia Nicolae. CercetÄrile de la Mitoc (r. SÄveni, reg. Suceava) / Les recherches de Mitoc. In: Materiale Ći cercetÄri arheologice, N°6 1959. pp. 11-23
Relation for the nonequilibrium population of the interface states: effects on the bias dependence of the ideality factors
By an analysis of the exchange of carriers through a semiconductor junction, a general relationship for the nonequilibrium population of the interface states in Schottky barrier diodes has been derived. Based on this relationship, an analytical expression for the ideality factor valid in the whole range of applied bias has been given. This quantity exhibits two different behaviours depending on the value of the applied bias with respect to a critical voltage. This voltage, which depends on the properties of the interfacial layer, constitutes a new parameter to complete the characterization of these junctions. A simple interpretation of the different behaviours of the ideality factor has been given in terms of the nonequilibrium charging properties of interface states, which in turn explains why apparently different approaches have given rise to similar results. Finally, the relevance of our results has been considered on the determination of the density of interface states from nonideal current-voltage characteristics and in the evaluation of the effects of the interfacial layer thickness in metal-insulator-semiconductor tunnelling diodes
Generation of nearly nondiffracting Bessel beams with a FabryâPerot interferometer
A new concept for generating zero-order Bessel beams was studied theoretically. The spatial intensity distribution was calculated numerically using a wave optics model. Approximate analytical expressions were derived to describe the radial intensity distribution in planes perpendicular to the optical axis of an imaging
lens.Texas InstrumentsNational Science FoundationOTKA Foundation of the Hungarian Academy of Science
The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests
The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the BĂŒkk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey
Study of Chitinase and Chitinolytic Activity of Lactobacillus Strains
The increasing consumer demand for less processed and more natural food products - while improving those productsâ quality, safety, and shelf-life â has raised the necessity of chemical preservative replacement. Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Chitinolytic enzymes are of biotechnological interest, since their substrate, chitin, is a major structural component of the cell wall of fungi, which are the main cause of the spoilage of food and raw plant material. Among the several organisms, many bacteria produce chitinolytic enzymes, however, this behaviour is not general. The chitinase activity of the lactic acid bacteria is scarcely known and studied. The aim of the present study was to select Lactobacillus strains that have genes encoding chitinase, furthermore, to detect expressed enzymes and to characterise their chitinase activity. Taking into consideration the importance of chitin-bindig proteins (CBPs) in the chitinase activity, CBPs were also examined. Five Lactobacillus strains out of 43 strains from 12 different species were selected by their chitinase coding gene. The presence of the chitinase and chitin-biding protein production were confirmed, however, no chitinolytic activity has been identified
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