Quality Incentives – Quality Outcome In Procured Public Transport, Case Study Stockholm

Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Photometric Variability in the Faint Sky Variability Survey

The Faint Sky Variability Survey (FSVS) is aimed at finding photometric and/or astrometric variable objects between 16th and 24th mag on time-scales between tens of minutes and years with photometric precisions ranging from 3 millimag to 0.2 mag. An area of 23 deg$^2$, located at mid and high Galactic latitudes, was covered using the Wide Field Camera (WFC) on the 2.5-m Isaac Newton Telescope (INT) on La Palma. Here we present some preliminary results on the variability of sources in the FSVS.Comment: 4 pages, 3 figures, to appear in 14th European Workshop on White Dwarfs, ASP Conference Series, eds. D. Koester, S. Moehle

Формалізація основних принципів взаємодії інвестора (кредитора) та позичальника (господарюючого суб’єкта)

Здійснено аналіз питань пов’язаних з організацією раціонального інвестування як з точки зору позичальника (господарюючого суб’єкта) так і з точки зору інвестора (кредитора). Проблему узгодження інтересів інвестора та позичальника сформульовано як багатокритеріальну задачу математичного програмування. Запропонована формалізація взаємодії господарюючого суб’єкта та інвестора за допомогою дослідження дискретного Марковського процесу, стани якого задаються вектором інтегральних показників діяльності кредитора та позичальника.This work comprises the rational investment organizationrelated issues analysis from the borrower’s (managing entity), as well as from the investor’s (creditor’s) point of view. The borrower and investor’s interests’ coordination issue is formulated as a mathematical programming multicriterion problem. The borrower and investor cooperation formalization with help of discreet Markov’s process study is introduced. The Markov’s process’ states are determined by the investor and borrower’s integral activities’ rates vector

A comparative analysis of the publication behaviour of MSCA fellows

MSCA applicants from South and Eastern European countries underperform researchers from North Western Europe before receiving the grant. However, the median difference disappears by the time of the grant and in the period after this. Due to a higher number of outliers (top performers) among the researchers from North Western Europe, the mean impact scores do remain significantly higher

Short timescale variability in the Faint Sky Variability Survey

We present the V band variability analysis of the point sources in the Faint Sky Variability Survey on time scales from 24 minutes to tens of days. We find that about one percent of the point sources down to V = 24 are variables. We discuss the variability detection probabilities for each field depending on field sampling, amplitude and timescale of the variability. The combination of colour and variability information allows us to explore the fraction of variable sources for different spectral types. We find that about 50 percent of the variables show variability timescales shorter than 6 hours. The total number of variables is dominated by main sequence sources. The distribution of variables with spectral type is fairly constant along the main sequence, with 1 per cent of the sources being variable, except at the blue end of the main sequence, between spectral types F0--F5, where the fraction of variable sources increases to about 2 percent. For bluer sources, above the main sequence, this percentage increases to about 3.5. We find that the combination of the sampling and the number of observations allows us to determine the variability timescales and amplitudes for a maximum of 40 percent of the variables found. About a third of the total number of short timescale variables found in the survey were not detected in either B or/and I. These show a similar variability timescale distribution to that found for the variables detected in all three bands.Comment: 14 pages, 12 figures and 4 tables. Accepted for publication in MNRA

Identification of 13 DB + dM and 2 DC + dM binaries from the Sloan Digital Sky Survey

We present the identification of 13 DB + dM binaries and 2 DC + dM binaries from the Sloan Digital Sky Survey (SDSS). Before the SDSS only 2 DB + dM binaries and 1 DC + dM binary were known. At least three, possibly 8, of the new DB + dM binaries seem to have white dwarf temperatures well above 30000 K which would place them in the so called DB-gap. Finding these DB white dwarfs in binaries may suggest that they have formed through a different evolutionary channel than the ones in which DA white dwarfs transform into DB white dwarfs due to convection in the upper layers.Comment: 4 pages, 2 figures, accepted for publication in A&A Letter

A ZZ Ceti white dwarf in SDSS J133941.11+484727.5

We present time-resolved spectroscopy and photometry of the cataclysmic variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in the Sloan Digital Sky Survey Data Release 4. The orbital period determined from radial velocity studies is 82.524(24)min, close to the observed period minimum. The optical spectrum of SDSS1339 is dominated to 90% by emission from the white dwarf. The spectrum can be successfully reproduced by a three-component model (white dwarf, disc, secondary) with Twd=12500K for a fixed log g=8.0, d=170pc, and a spectral type of the secondary later than M8. The mass transfer rate corresponding to the optical luminosity of the accretion disc is very low,~1.7x10^-13Msun/yr. Optical photometry reveals a coherent variability at 641s with an amplitude of 0.025mag, which we interpret as non-radial pulsations of the white dwarf. In addition, a long-period photometric variation with a period of either 320min or 344min and an amplitude of 0.025mag is detected, which bears no apparent relation with the orbital period of the system. Similar long-period photometric signals have been found in the CVs SDSSJ123813.73-033933.0, SDSSJ204817.85-061044.8, GW Lib and FS Aur, but so far no working model for this behaviour is available.Comment: MNRAS, in press, 8 pages, 10 figures, some figures downgraded to meet the file size constraint of arxiv.or