In this paper, we study an M/G/1 queue with two phases of heterogeneous service. A first essential service is provided to all arriving customers. Upon completion of this service, a customer can either opt for a second phase of service or can leave the system. A customer, who finds the server busy, either leaves the system with probability (1-α) or joins an orbit with probability α. From the orb...

This paper examines firms’ product policies when they sell an add-on (Internet service) to a base good (hotel rooms) under vertical differentiation (fourvs. three-star hotels). Theoretical analysis uncovers the differential roles of add-ons for vertically differentiated firms. A firm with higher base quality always sells an add-on as optional so that higher-taste consumers self-select to buy it...

There has been a precipitous decline in the number of rural communities across Canada providing local maternity care. The evidence suggests that the outcome for newborns may be worse as a result. There is also an emerging understanding of the significant physiological and psychosocial consequences for rural parturient women. Because they cannot plan for birth with any certainty, many of them ex...

Abstract: The present investigation deals with M/G/1 retrial queue with unreliable server and general retrial times. The server is subject to breakdowns and takes some setup time before starting the repair. The server renders first essential phase of service (FES) to all the arriving customers whereas second optional phase services (SOS) are provided after FES to only those customers who opt fo...

This document defines mechanisms that provide an asynchronous message notification delivery service for the Network Configuration protocol (NETCONF). This is an optional capability built on top of the base NETCONF definition. This document defines the capabilities and operations necessary to support this service. Chisholm & Trevino Standards Track [Page 1] RFC 5277 NETCONF Event Notifications J...

Reward-based scheduling refers to the problem in which there is a reward associated with the execution of a task. In our framework, each real-time task comprises a mandatory and an optional part. The mandatory part must complete before the task's deadline, while a nondecreasing reward function is associated with the execution of the optional part, which can be interrupted at any time. Imprecise...

Traditional public transport is evolving towards more flexible services and operation modes in order to better serve the needs of the population, capture additional demand, and increase its profitability. The transportation system that we study integrates traditional bus transportation and on-demand services. Demand-responsive lines provide a classical, scheduled, transportation service among a...

The aim of this paper is to describe some properties of what we call “optional co-composition”. We are interested, more precisely, in the role of optional co-composition in two disambiguation tasks: both word sense and structural disambiguation. Concerning the second task, some experiments were performed on a Portuguese corpus.