Consumer Behavior

We analyze a continuous-time, two-stage production/inventory system. In the first stage, a common intermediate product is produced in batches, and possibly stored. In the second phase, the intermediate product is fabricated into n distinct finished products. Several finished products may be included in a single production batch of limited capacity to exploit economies of scale. We propose a planning methodology to address the combined problem of joint setup costs and capacity limits (per setup).

In many important combinatorial optimization problems, such as bin packing, allocating customer classes to queueing facilities, vehicle routing, multi-item inventory replenishment and combined routing/inventory control, an optimal partition into groups needs to be determined for a finite collection of objects; each is characterized by a single attribute. The cost is often separable in the groups and the group cost often depends on the cardinality and some aggregate measure of the attributes, such as the sum or the maximum element.

Similarity scaling often requires subjects to produce such a large number of judgments that fatigue may become a problem. Yet it remains unclear just how respondent fatigue affects similarity perceptions and resulting judgments. The present study uses a categorization perspective to examine the effects of fatigue on similarity judgments. The results suggest that subjects rely increasingly on category membership as they progress through a similarity judgment task.

In most vehicle routing problems, a given set of customers is to be partitioned into a collection of regions each of which is assigned to a single vehicle starting at a depot and returning there after visiting all of the region's customers exactly once in a route. In this paper we consider problem settings where the cost of a route may depend on its length ϑ as well as m, the number of points on the route, according to some general function f(ϑ,m), assumed to be nondecreasing and concave in ϑ.

This article explores the profit-sharing aspects of codevelopment agreements and focuses specifically on the nature of the city's financial involvement. Cities are increasingly using a vast array of financial mechanisms, including loan paybacks, participatory leases, and equity participations, to give them a more direct financial stake in projects. Sagalyn examines the financial structures of several codevelopment projects throughout the country.

We consider a single-server queueing system with Poisson arrivals and general service times. While the server is up, it is subject to breakdowns according to a Poisson process. When the server breaks down, we need to repair the server immediately by initiating one of two available repair operations. The operating costs of the system include customer holding costs, repair costs and running costs. The objective is to find a corrective maintenance policy that minimizes the long-run average operating costs of the system. The problem is formulated as a semi-Markov decision process.

This article treats the dynamic lot size model with quantity discount in purchase price. We study the problem with two different cost structures: the all-units-discount cost structure and the incremental-discount cost structure. We solve the problem under both discount cost structures by dynamic programming algorithms of complexity O(T3) and O(T2), respectively, with T the number of periods in the planning horizon.

We consider distribution systems with a depot and many geographically dispersed retailers each of which faces external demands occurring at constant, deterministic but retailer specific rates. All stock enters the system through the depot from where it is distributed to the retailers by a fleet of capacitated vehicles combining deliveries into efficient routes. Inventories are kept at the retailers but not at the depot.

We consider a single-server queueing system with Poisson arrivals and general service times. While the server is up, it is subject to breakdowns according to a Poisson process. When the server breaks down, we may either repair the server immediately or postpone the repair until some future point in time. The operating costs to the system include customer holding costs, repair costs and running costs. The objective is to find a corrective maintenance policy which minimizes the long-run average operating costs of the system. The problem is formulated as a semi-Markov decision process.