A large-deviations analysis of the GI/GI/1 SRPT queue

We consider a GI/GI/1 queue with the shortest remaining processing time discipline (SRPT) and light-tailed service times. Our interest is focused on the tail behavior of the sojourn-time distribution. We obtain a general expression for its large-deviations decay rate. The value of this decay rate critically depends on whether there is mass in the endpoint of the service-time distribution or not. An auxiliary priority queue, for which we obtain some new results, plays an important role in our analysis. We apply our SRPT-results to compare SRPT with FIFO from a large-deviations point of view.Comment: 22 page

Bounds for avalanche critical values of the Bak-Sneppen model

We study the Bak-Sneppen model on locally finite transitive graphs $G$, in particular on Z^d and on T_Delta, the regular tree with common degree Delta. We show that the avalanches of the Bak-Sneppen model dominate independent site percolation, in a sense to be made precise. Since avalanches of the Bak-Sneppen model are dominated by a simple branching process, this yields upper and lower bounds for the so-called avalanche critical value $p_c^{BS}(G)$. Our main results imply that 1/(Delta+1) <= \leq p_c^{BS}(T_Delta) \leq 1/(Delta -1)$, and that$1/(2d+1)\leq p_c^{BS}(Z^d)\leq 1/(2d)+ 1/(2d)^2+O(d^{-3}), as d\to\infty.Comment: 19 page

Misja organizacji a misja uniwersytetu

This article presents the different definitions of university mission, the current understanding of the term, its various functions and the context in which it is developed and applied. It also discusses the reasons why it is necessary to redefine university mission. These reasons have two different sources. On the one hand, the university environment and the relations between the universities and the State have changed and on the other hand, the contemporary university is facing new demands and the methods of teaching and doing research have altered.Celem artykułu jest przedstawienie różnych definicji misji uniwersytetu, jej obecnego znaczenia, zróżnicowanych funkcji, jakie pełni, oraz kontekstu, w jakim jest tworzona i wykorzystywana. Autorka ukazuje także powody uzasadniające nowy sposób rozumienia misji. Wynikają one z jednej strony z charakteru zmian w otoczeniu uczelni i w stosunkach między państwem a szkołami wyższymi, które zadecydowały o karierze tego pojęcia, z drugiej zaś z oczekiwań stawianych wobec współczesnego uniwersytetu oraz zmian w prowadzeniu dydaktyki i uprawianiu nauki

Albania: Trends and patterns, proximate determinants and policies of fertility change

For a very long time, Albania has had one of the highest levels of fertility in Europe: in 2002 the total fertility rate of 2.2 children per woman was the highest in Europe. Although this current level is high, the country has experienced a rapid fertility reduction during the last 50 years: a TFR decline from 7 to 2.2. This reduction has occurred in the absence of modern contraception and abortion, which indicates the significance of investments in the social agenda during the communist regime that produced policies with indirect effects on fertility. Most significant of these were policies focused on education, in particular on female education. Social and demographic settings for a further fertility reduction in Albania have been present since 1990. Contraception and abortion have been legalized and available since the early 1990s, but knowledge of their use is still not widespread in the country, largely due to the interplay between traditional and modern norms of Albanian society. This chapter points out that future fertility levels will be determined not only by new policies that might be introduced, but predominantly by the balance of this interplay.Albania, childbearing, Europe, fertility, fertility change

The effect of service time variability on maximum queue lengths in M^X/G/1 queues

We study the impact of service-time distributions on the distribution of the maximum queue length during a busy period for the M^X/G/1 queue. The maximum queue length is an important random variable to understand when designing the buffer size for finite buffer (M/G/1/n) systems. We show the somewhat surprising result that for three variations of the preemptive LCFS discipline, the maximum queue length during a busy period is smaller when service times are more variable (in the convex sense).Comment: 12 page