2,665 research outputs found

    Analysis of the BATSE Continuous MER data

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    The CGRO/BATSE database includes many types of data such as the 16-channel continuous background or medium energy resolution burst data (CONT and MER data types). We have calculated some four hundred burst's medium energy resolution spectra and Principal Component Analysis has been applied. We found five components can describe GRBs' spectra.Comment: 4 pages, 2 figures, accepted in Nuovo Ciment

    An empirical research of the factors determining customer behaviour in food retail stores

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    For years the Institute of Marketing at Szent István University has been conducting research in customer and consumer behaviour. This research project focuses on which food shops retail customers choose when it comes to traditional food. This paper briefly summarizes qualitative findings and offers a preliminary analysis of the project’s quantitative stage. Using six focus groups, the qualitative phase tried to identify factors that impact on how food retail shops were chosen. The goal was to pinpoint individual steps in the decision-making process. Shops selected for study were: hypermarkets, supermarkets, discount stores, small shops, markets, specialised stores and cash & carry stores. Following this, using data from the qualitative results, a national representative survey was conducted. The survey used a standardised questionnaire with 1,019 subjects. The survey concentrated on hypermarket customers, as well as identifying this customer group’s segments, and analysing their decision-making traits.Kelly’s repertory grid technique, Qualitative research, Quantitative research, Monroe & Guiltinan’s store choice model, Donovan & Rossiter’s store atmosphere model, store characteristics, segments of hypermarket patrons., Research Methods/ Statistical Methods,

    Comparing the observed properties of the GRBs detected by the Fermi and Swift satellites

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    We studied the distribution of the GRBs, observed by the Fermi satellite, in the multidimensional parameter space consisting of the duration, Fluence, Peak flux and Peak energy (if it was available). About 10% of the Fermi bursts was observed also by the Swift satellite. We did not find significant differences between the Peak flux and Peak energy of GRBs observed and not observed also by the Swift satellite. In contrast, those GRBs detected also by the Swift satellite had significantly greater Fluence and duration. We did a similar study for the GRBs detected by the Swift satellite. About 30% percent of these bursts was also measured by the Fermi satellite. We found a significant difference in the Fluence, Peak flux and Photon index but none in duration. These differences may be accounted for the different construction and observing strategy of the Fermi and Swift satellites.Comment: 7th Huntsville Gamma-Ray Burst Symposium, GRB 2013: paper 5 in eConf Proceedings C130414

    Properties of the intermediate type of gamma-ray bursts

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    Gamma-ray bursts can be divided into three groups ("short", "intermediate", "long") with respect to their durations. The third type of gamma-ray bursts - as known - has the intermediate duration. We show that the intermediate group is the softest one. An anticorrelation between the hardness and the duration is found for this subclass in contrast to the short and long groups.Comment: In Sixteenth Maryland Astrophysics Conferenc

    A Principal Component Analysis of the 3B Gamma-Ray Burst Data

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    We have carried out a principal component analysis for 625 gamma-ray bursts in the BATSE 3B catalog for which non-zero values exist for the nine measured variables. This shows that only two out of the three basic quantities of duration, peak flux and fluence are independent, even if this relation is strongly affected by instrumental effects, and these two account for 91.6% of the total information content. The next most important variable is the fluence in the fourth energy channel (at energies above 320 keV). This has a larger variance and is less correlated with the fluences in the remaining three channels than the latter correlate among themselves. Thus a separate consideration of the fourth channel, and increased attention on the related hardness ratio H43H43 appears useful for future studies. The analysis gives the weights for the individual measurements needed to define a single duration, peak flux and fluence. It also shows that, in logarithmic variables, the hardness ratio H32H32 is significantly correlated with peak flux, while H43H43 is significantly anticorrelated with peak flux. The principal component analysis provides a potentially useful tool for estimating the improvement in information content to be achieved by considering alternative variables or performing various corrections on available measurementsComment: Ap.J., accepted 12/9/97; revised version contains a new appendix, somewhat expanded discussion; latex, aaspp4, 15 page