8 research outputs found
First results of site testing program at Mt. Shatdzhatmaz in 2007 - 2009
We present the first results of the site testing performed at
Mt.~Shatdzhatmaz at Northern Caucasus, where the new Sternberg astronomical
institute 2.5-m telescope will be installed. An automatic site monitor
instrumentation and functionality are described together with the methods of
measurement of the basic astroclimate and weather parameters. The clear night
sky time derived on the basis of 2006 -- 2009 data amounts to 1340 hours per
year. Principle attention is given to the measurement of the optical turbulence
altitude distribution which is the most important characteristic affecting
optical telescopes performance. For the period from November 2007 to October
2009 more than 85\,000 turbulence profiles were collected using the combined
MASS/DIMM instrument. The statistical properties of turbulent atmosphere above
the summit are derived and the median values for seeing ~arcsec
and free-atmosphere seeing ~arcsec are determined.
Together with the estimations of isoplanatic angle ~arcsec and
time constant \tau_0 = 2.58 \mbox{ ms}, these are the first representative
results obtained for Russian sites which are necessary for development of
modern astronomical observation techniques like adaptive optics.Comment: Accepted for publication in MNRAS, 17 pages, 15 figure
Ukrainian financial markets: an examination of calendar anomalies
Purpose – This study aims to examine the market returns of the Ukrainian stock and bond markets to determine whether they exhibit calendar anomalies including the January effect, weekend effect, and turn-of-the-month (TOM) effect. Ukraine provides an opportunity to examine the efficiency of an emerging market, adding to the extensive body of research on calendar anomalies. Design/methodology/approach – Regression analysis is used to examine the relationship between January returns vs non-January returns, Monday returns vs non-Monday returns, and TOM returns vs non-TOM returns. Non-parametric t-tests and Wilcoxon signed rank tests are also used to examine TOM returns vs the rest of the month returns. Findings – There is no evidence of a January effect or a weekend effect in the Ukrainian stock and bond markets. However, our results support a TOM effect in the Ukrainian stock market. The mean daily TOM return is 0.35 vs 0.24 per cent for the rest of the month. Additionally, in 63 per cent of the months, the mean daily TOM return exceeds the return for the rest of the month. Research limitations/implications – The data are limited to five-years of daily returns and two different Ukrainian indexes. Thus, the results could be biased by the time period analyzed. The results are important for portfolio managers and investors as they can benefit from the TOM effect, but not the January effect and weekend effect. Originality/value – This is the first study to our knowledge that has extensively examined the calendar anomalies in the Ukrainian stock and bond markets.Capital structure, Debt capital, Investment appraisal, Investments, Performance management