The waiting time distribution for a correlated queue with exponential interarrival and service times

We are concerned with the analysis of the waiting time distribution in an $M∕M∕1$ queue in which the interarrival time between the $n$th and the $(n+1)$th customers and the service time of the $n$th customer are correlated random variables with Downton’s bivariate exponential distribution. In this paper we show that the conditional waiting time distribution, given that the waiting time is positive, is exponential.     

Random version of Dvoretzky’s theorem in ℓpn

We study the dependence on $\epsilon$ in the critical dimension $k(n,p,\epsilon )$ for which one can find random sections of the ${?}_p^n$-ball which are $(1+\epsilon )$-spherical. We give lower (and upper) estimates for $k(n,p,\epsilon )$ for all eligible values $p$ and $\epsilon$ as $n\to \infty$, which agree with the sharp estimates for the extreme values $p=1$ and $p=\infty$. Toward this end, we provide tight bounds for the Gaussian concentration of the ${?}_p$-norm.     

Controllability of a multichannel system

We consider the system consisting of K coupled acoustic channels with the different sound velocities $c_j$. Channels are interacting at any point via the pressure and its time derivatives. Using the moment approach and the theory of exponential families with vector coefficients we establish two controllability results: the system is exactly controllable if(i) the control $u_j$ in the jth channel acts longer than the double travel time of a wave from the start to the end of the j-th channel;(ii) all controls $u_j$ act more than or equal to the maximal double travel time.     

Improved stability and H∞ performance for neutral systems with uncertain Markovian jump

This paper addresses the problem of the delay-dependent stability and $H\infty$ performance for neutral systems with uncertain Markovian jump; the uncertainty of Markovian jump refers to the partial information on transition probability. In order to highlight the methods for the analysis of the systems, the neutral delay is assumed same as discrete delay. By the novel constructed Lyapunov functional, combining with the delay decomposition technique and free matrices, and using the new inequality rather than the Jensen inequality, the delay-dependent stability conditions are firstly obtained for the two kinds of neutral dynamical systems. Based on the stability condition, the $H\infty$ performance result for the systems with Markovian jump is secondly provided. All of the delay-dependent stabilization results are formulated in terms of LMIs, which can be easily checked by the LMI control toolbox in Matlab. Finally, two numerical examples are given to show the validity and potential of the developed criteria.     

The Bradley–Terry condition is L1-testable

We provide an algorithm with constant running time that given a weighted tournament $T$, distinguishes with high probability of success between the cases that $T$ can be represented by a Bradley–Terry model, or cannot even be approximated by one. The same algorithm tests whether the corresponding Markov chain is reversible.