Bressloff Paul C
Department of Mathematics, University of Utah, Salt Lake City, Utah 84112, USA.
Phys Rev E. 2020 Sep;102(3-1):032109. doi: 10.1103/PhysRevE.102.032109.
We use queueing theory to develop a general framework for analyzing search processes with stochastic resetting, under the additional assumption that following absorption by a target, the particle (searcher) delivers a packet of resources to the target and the search process restarts at the reset point x_{r}. This leads to a sequence of search-and-capture events, whereby resources accumulate in the target under the combined effects of resource supply and degradation. Combining the theory of G/M/∞ queues with a renewal method for analyzing resetting processes, we derive general expressions for the mean and variance of the number of resource packets within the target at steady state. These expressions apply to both exponential and nonexponential resetting protocols and take into account delays arising from various factors such as finite return times, refractory periods, and delays due to the loading or unloading of resources. In the case of exponential resetting, we show how the resource statistics can be expressed in terms of the MFPTs T_{r}(x_{r}) and T_{r+γ}(x_{r}), where r is the resetting rate and γ is the degradation rate. This allows us to derive various general results concerning the dependence of the mean and variance on the parameters r,γ. Our results are illustrated using several specific examples. Finally, we show how fluctuations can be reduced either by allowing the delivery of multiple packets that degrade independently or by having multiple independent searchers.
我们运用排队论来构建一个通用框架,用于分析具有随机重置的搜索过程。在此额外假设下,即粒子(搜索者)被目标吸收后,会向目标传递一包资源,且搜索过程在重置点(x_{r})重新开始。这会导致一系列搜索与捕获事件,在此过程中,资源在资源供应和降解的综合作用下在目标中积累。我们将(G/M/∞)排队论与一种用于分析重置过程的更新方法相结合,推导出了稳态下目标内资源包数量的均值和方差的通用表达式。这些表达式适用于指数型和非指数型重置协议,并考虑了诸如有限返回时间、不应期以及资源加载或卸载导致的延迟等各种因素引起的延迟。在指数型重置的情况下,我们展示了如何根据首次通过时间(T_{r}(x_{r}))和(T_{r + γ}(x_{r}))来表示资源统计量,其中(r)是重置率,(γ)是降解率。这使我们能够得出关于均值和方差对参数(r)、(γ)依赖性的各种通用结果。我们通过几个具体例子来说明我们的结果。最后,我们展示了如何通过允许独立降解的多个包的传递或通过有多个独立搜索者来减少波动。