Data

This study illustrates a statistical procedure that can be used to estimate the fraction of a given population experiencing a “rare” event during a long time period, given a few days of observation. In an automobile usage context, the rare event could be the occurrence of an automobile occupancy of four or more persons and/or a travel distance of 100 miles or more on any given day. The technique, which can be important for the design of durable goods, is illustrated with four numerical examples.

This note presents upper bounds for the minimum distance needed to visit n points in a unit circle, with a vehicle fleet based at its center and allowed to visit a maximum of q points per vehicle tour. The paper shows that the minimum distance can never exceed: [2n/q]+ + pi q. If points are randomly and uniformly distributed, and travel can only take place on a ring-radial network, the paper also proves that for q = 0(n**beta), 0 less than beta less than 1/2, the average minimum distance does not exceed: [4n/3q] + 0.82(pi n)**1/2 + 0(q). For the Euclidean metric, it is claimed that a...

This paper proposes an algorithm that automatically translates the “continuum approximation” (CA) recipes for location problems into discrete designs. It applies to terminal systems, but can also be used for other logistics problems. The study also systematically compares the logistics costs predicted by the CA approach with the actual costs for discrete designs obtained with the automated procedure. The predictions are quite accurate. The paper also gives conditions under which the discrete solution has a small optimality gap.

This paper analyzes the bullwhip effect in single-echelon supply chains driven by arbitrary customer demands and operated nondeterministically. The supply chain, with stochastic system parameters, is modeled as a Markovian jump linear system. The paper presents robust analytical conditions to diagnose the bullwhip effect and bound its magnitude. The tests are independent of the customer demand. Examples are given. Ordering policies that pass these tests, and thus avoid the bullwhip effect in random environments for arbitrary customer demands, are shown to exist. The paper also presents...