In this paper, several alternative formulations for the multi-floor facility layout problem are presented. Elevators handle the material transport between different floors. Elevators are allowed to service either all floors or a contiguous set of floors. In this formulation, elevators can be located anywhere within the floors provided they do not overlap with departments. The departments and fl...

Different alley flooring systems have been found to influence claw health and locomotion among dairy cows in cubicle barns. The ability to keep the alley floors clean and dry is part of this. It is, however, challenging to keep the alleys clean at all time. Different cleaning regimes are used, and barns are equipped with a diversity of scrapers and alley surfaces. Scrapers are earlier found to ...

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Sticky demand – sticky nominal spending – acts as a substitute for sticky prices. In an inventorytheoretic model of the demand for money, monetary injections are offset by endogenous movements in velocity that keep nominal spending flat. When embedded in a sticky price model, this reduces the model’s reliance on implausibly large amounts of exogenous stickiness. For example: 6 months asset mark...

A matroid is sticky if any two of its extensions by disjoint sets can be glued together along the common restriction (that is, they have an amalgam). The sticky matroid conjecture asserts that a matroid is sticky if and only if it is modular. Poljak and Turzı́k proved that no rank-3 matroid having two disjoint lines is sticky. We show that, for r ≥ 3, no rank-r matroid having two disjoint hyperp...

This paper shows that switching the dominant use of household-specific sticky wages in the New Keynesian model (Erceg, Henderson, and Levin 2000) for firm-specific sticky wages has qualitative and quantitative consequences. First, the model with firm-specific sticky wages incorporates endogenous changes in the rate of unemployment, whereas there is no unemployment with household-specific sticky...

Safety floors (also known as compliant floors) may reduce the risk of fall-related injuries by attenuating impact force during falls, but are only practical if they do not negatively affect balance and mobility. In this study, we evaluated seven safety surfaces based on their ability to attenuate peak femoral neck force during simulated hip impacts, and their influence on center of pressure (CO...

Despite the importance of housing for people’s well-being, there is little evidence on the causal impact of housing and housing improvement programs on health and welfare. In this paper, we help to fill this gap by investigating the impact of a largescale effort by the Mexican Government to replace dirt floors with cement floors on child health and adult happiness. We find that replacing dirt f...