George G. Polak

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Recent extreme economic developments nearing a worst-case scenario motivate further examination of minimax linear programming approaches for portfolio optimization. Risk measured as the worst-case return is employed and a portfolio from maximizing returns subject to a risk threshold is constructed. Minimax model properties are developed and parametric(More)
Clustering problems are often difficult to solve due to nonlinear cost functions and complicating constraints. Set partitioning formulations can help overcome these challenges, but at the cost of a very large number of variables. Therefore, techniques such as delayed column generation must be used to solve these large integer programs. The underlying(More)
In a storage-and-retrieval device, items are stored in the slots of the storage bank for subsequent retrieval by a picking mechanism as needed. Many varieties of these robotic devices are in use in manufacturing as well as in logistics and in computer peripherals. The problem of assigning items by type to storage slots in order to minimize the total(More)
In the manufacture of printed circuit boards, electronic components are attached to a blank board by one or more pick-and-place machines. Each machine has component magazines that house replaceable feeders. Since component requirements differ among board types, each change of feeders can improve processing time but indicates a machine setup. We develop an(More)
Printed circuit boards appear in a wide array of products and thus their production is crucial to the contemporary electronics industry. A global approach to planning the complex and multi-stage production process is currently intractable. Nonetheless, significant improvements can be made by integrating closely related elements within the planning process.(More)
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