purpose: this paper has two main goals: first, to evaluate the position of geological survey of iran library through the assessment of internal (strengths and weaknesses) and external (opportunities and threats) environment; and then, provide solutions and strategies to help library managers and administrators to achieve their goals, missions and visions. methodology: among the existing models,...

Currently used parallel best rst branch-and-bound algorithms either suuer from contention at a centralized priority queue or can only approximate the best rst strategy. Bottleneck free algorithms for parallel priority queues are known but they cannot be implemented very eeciently on contemporary machines. We present quite simple randomized algorithms for parallel priority queues on distributed ...

We present a practical meldable priority queue implementation. All priority queue operations are very simple and their logarithmic time bound holds with high probability, which makes this data structure more suitable for real-time applications than those with only amortized performance guarantees. Our solution is also space-eecient, since it does not require storing any auxiliary information wi...

In this paper we report on a study of a two level preemptive priority queue with balking and reneging for lower priority level. The inter-arrival and the service times for both levels follow exponential distribution. We use a finite difference equation approach for solving the balance equations of the governing queuing model whose states are described by functions of one independent variable. H...

Well-known results on the ergodicity of queues with preemptive priority were obtained under assumption that jobs arrive according to Poisson process. This assumption, however, does not always hold true in practice. In our work we find sufficient conditions for two classes a single server, where interarrival times high-priority have either Erlang or hyperexponential distribution and low-priority...

A limitation in the design of the interface of C++ standard priority queues is addressed. The use of priority queues in Dijkstra’s shortest path search algorithm is used as an example. Priority queues are often implemented using heaps. There is a problem, as it may be necessary to change the priority of an element while it is in the queue, but finding the element from within a heap is costly. T...

In this paper, we investigate a simplified head-of-the-line with priority jumps (HOL-PJ) scheduling discipline. Therefore, we consider a discrete-time single-server queueing system with two priority queues of infinite capacity and with a newly introduced HOL-PJ priority scheme. We derive expressions for the probability generating function of the system contents and the packet delay. Some perfor...