We show how to transform any inequality defining a facet of some 0/1-polytope into an inequality defining a facet of the acyclic subgraph polytope. While this facet-recycling procedure can potentially be used to construct ‘nasty’ facets, it can also be used to better understand and extend the polyhedral theory of the acyclic subgraph and linear ordering problems.

The computer program WPACKING was validated using bin data for three different bin conditions: 1) a smooth-walled bin filled with wheat, 2) a corrugated-walled bin filled with wheat, and 3) a corrugated-walled bin filled with corn. WPACKING is a computer program which utilizes the differential form of Janssen’s equation to predict the pressures and amount of material stored in a bin. The differ...

We study a variety of NP-hard bin packing problems under a divisibility constraint that generalizes the often encountered situation in which all item sizes are powers of 2. For ordinary one-dimensional bin packing, we show that First Fit Decreasing produces optimal packings under this restriction, and that if in addition the largest item size divides the bin capacity, then even the less powerfu...

Page-coloring and bin-hopping are two well-known page mapping schemes for reducing cache connicts. Previous work found bin-hopping to have 4% less cache miss rate than page-coloring on uniprocessor machines. Using execution-driven simulations, we nd that bin-hopping signiicantly outperforms simplistic page-coloring on CC-NUMA multipro-cessors. In certain cases, bin-hopping has 32% to 58% less e...

“why” mind-set. We are particularly interested in your thoughts about recycling. In particular, we are interested in your thoughts about why you would recycle. For example, what are the underlying reasons for recycling, for what purpose would you recycle, etc.? Please take some time below to explain why you would go about recycling.

A gas-phase reactor with reversible exothermic reactions is the classical example of the many tradeoffs between operating costs and capital costs. Because per-pass conversion is limited by chemical equilibrium, recycle is almost always needed, and this gas recycle is expensive because of the high capital cost and high energy cost of gas compression. At low temperatures, conversion is limited by...

We show that modified versions of the linear congruential generator and the shift register generator are provably good for amplifying the correctness of a probabilistic algorithm. More precisely, if r random bits are needed for a BPP algorithm to be correct with probability at least 2/3, then O(r + k) bits are needed to improve this probability to 1 − 2−k. We also present a different pseudo-ran...