We consider a two-stage service policy for a Poisson arrival queueing system. The idle server starts to work with ordinary service rate when a customer arrives. If the number of customers in the system reaches N, the service rate gets faster and continues until the system becomes empty....

We consider a G / M / 1 queue with two-stage service policy. The server starts to serve with rate of μ 1 customers per unit time until the number of customers in the system reaches λ. At this moment, the service rate is changed to that of μ 2 customers per unit time and this rate continues...

We consider a two-stage service policy for a Poisson arrival queueing system. The idle server starts to work with ordinary service rate when a customer arrives. If the number of customers in the system reaches N, the service rate gets faster and continues until the system becomes empty....

We consider a G / M / 1 queue with two-stage service policy. The server starts to serve with rate of μ<Subscript>1</Subscript> customers per unit time until the number of customers in the system reaches λ. At this moment, the service rate is changed to that of μ<Subscript>2</Subscript> customers per unit time and this rate continues...</subscript></subscript>

In this paper we reconsider the international market integration, starting at high levels in the late nineteenth century, collapsing between the wars, and recovering gradually after 1945 to reach levels comparable to pre-1914 in the 1990's. The empirical evidence we survey suggests that in some...