Retrial Queue with Lattice Distribution of Inter-Arrival Times and Constant Retrial Rate

Author(s):  
Che Soong Kim ◽  
Valentina Klimenok ◽  
Alexander Dudin
2000 ◽  
Vol 14 (1) ◽  
pp. 9-26 ◽  
Author(s):  
Anthony C. Brooms

Customers arrive sequentially to a service system where the arrival times form a Poisson process of rate λ. The system offers a choice between a private channel and a public set of channels. The transmission rate at each of the public channels is faster than that of the private one; however, if all of the public channels are occupied, then a customer who commits itself to using one of them attempts to connect after exponential periods of time with mean μ−1. Once connection to a public channel has been made, service is completed after an exponential period of time, with mean ν−1. Each customer chooses one of the two service options, basing its decision on the number of busy channels and reapplying customers, with the aim of minimizing its own expected sojourn time. The best action for an individual customer depends on the actions taken by subsequent arriving customers. We establish the existence of a unique symmetric Nash equilibrium policy and show that its structure is characterized by a set of threshold-type strategies; we discuss the relevance of this concept in the context of a dynamic learning scenario.


Top ◽  
2012 ◽  
Vol 22 (2) ◽  
pp. 509-529 ◽  
Author(s):  
Chesoong Kim ◽  
Valentina Klimenok ◽  
Alexander Dudin

2005 ◽  
Vol 156 (6) ◽  
pp. 207-210 ◽  
Author(s):  
Claudio Defila

Numerous publications are devoted to plant phenological trends of all trees, shrubs and herbs. In this work we focus on trees of the forest. We take into account the spring season (leaf and needle development) as well as the autumn (colour turning and shedding of leaves) for larch, spruce and beech, and,owing to the lack of further autumn phases, the horse chestnut. The proportion of significant trends is variable, depending on the phenological phase. The strongest trend to early arrival in spring was measured for needles of the larch for the period between 1951 and 2000 with over 20 days. The leaves of the horse chestnut show the earliest trend to turn colour in autumn. Beech leaves have also changed colour somewhat earlier over the past 50 years. The trend for shedding leaves, on the other hand, is slightly later. Regional differences were examined for the growth of needles in the larch where the weakest trends towards early growth are found in Canton Jura and the strongest on the southern side of the Alps. The warming of the climate strongly influences phenological arrival times. Trees in the forest react to this to in a similar way to other plants that have been observed (other trees, shrubs and herbs).


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