In this paper, we consider retrial queueing systems with batch arrivals in which the server is subject to controllable interruptions (called vacations) and random interruptions (breakdowns). No specific assumption is taken regarding probability distributions of parametric random variables. The purpose of this work is to show effect of above mentioned parameters (in particular retrial and breakd...

Distributed Denial of Service (DDoS) attack is one the common that predominant in cyber world. DDoS poses a serious threat to internet users and affects availability services legitimate users. DDOS characterized by blocking particular service paralyzing victim’s resources so they cannot be used purpose leading server breakdown. uses networked devices into remotely controlled bots generates atta...

The purpose of this research paper was to propose a method which can be utilized to determine the different types of performance measures on the basis of the crisp values for the fuzzy queuing model which has an unreliable server and where the rate of arrival, the rate of service, the rate of breakdown and the rate of repair are all expressed as the fuzzy numbers. In this case the inter arrival...

In this paper single server homogeneous finite-source retrial queueing systems are investigated. The server is assumed to be subject to random breakdowns depending on whether it is busy or idle. The failure of the server may block or unblock the system’s operations and the service of the interrupted request may be resumed or the call can be transmitted to the orbit. All random variables involve...

This paper aims to find errors that lead to dialogue breakdowns in chat-oriented dialogue systems. We collected chat dialogue data, annotated them with dialogue breakdown labels, and collected comments describing the error that led to the breakdown. By mining the comments, we first identified error types. Then, we calculated the correlation between an error type and the degree of dialogue break...

there exists an arrangement in 5 in which a* follows all the Oi with i<k. Such sets Ssurely exist; for example, any set of m arrangements whose terminal elements are 1, 2, • • • , m, respectively, will obviously be ^-suitable for any k^m. The smallest cardinal number N such that there exists a set of N arrangements which is ^-suitable for m will be denoted by N(m, k); this is therefore a well d...

in this research, both resource allocation and reactive resource allocation problems in multi-server dynamic pert networks are analytically modeled, where new projects are expected to arrive according to a poisson process, and activity durations are also known as independent random variables with exponential distributions. such system is represented as a queuing network, where multi servers at ...