We study the approximability of instances of the minimum entropy set cover problem, parameterized by the average frequency of a random element in the covering sets. We analyze an algorithm combining a greedy approach with another one biased towards large sets. The algorithm is controled by the percentage of elements to which we apply the biased approach. The optimal parameter choice has a phase...

Tibetan gazelle Procapra picticaudata is a threatened and endemic species to the Qinghai-Tibet Plateau. With the method of group scan sampling, we observed the behaviours of males and females of the gazelle in the two summers of 2005 and 2006, in order to test the group size effect on group vigilance. We found that male gazelles were significantly more vigilant than the females at both group sc...

We provide regression analysis-based statistical models to explain the usage of wireless spectrum across four mid-size US cities in four frequency bands. Specifically, the variations in spectrum occupancy across space, time, and frequency are investigated and compared between different sites within the city as well as with other cities. By applying the mixed-effects models, several conclusions ...

The aim of the present study was to evaluate the effect of gamma irradiation on the hereditary structures of peripheral blood lymphocytes and to quantify this in a dose-effect study. We used adult male rabbits subjected to total gamma irradiation at a dose range of 0.5 − 3.0 Gy. Twenty-four (24) hours later, we began the process of culturing and determination of chromosome aberration frequency ...

csn1s1is one of the major genes encoding milk proteins of mammals. in this study we determined allele frequencies of csn1s1-5` flanking region as well as exon 17 variants and their effects on milk traits in three indigenous cattle breeds mazandarani, golpaygani (bos indicus) and sarabi (bos taurus) and holstein cattle in iran. csn1s1*b variant was nearly fixed in holstein but ranged from 0.40 t...