background: a substantial part of the public’s natural radiation dose is due to the inhalation of radon gas. most of the exposure occurs indoors where the airborne concentration of radon and its decay products is usually higher than outdoors. materials and methods: radon activity concentration has been measured twice in 50 classrooms in 5 levels (10 each) during summer and winter using solid-st...

The purpose of this research paper is to present a three-stage method using mathematicalprogramming techniques that finds high-quality solutions to the multi-floor facility layout problem. The first stage is a linear mixed-integer program that assigns departments to floors such that the total of the departmental interaction costs between floors is globally minimized. Subsequent stages find a lo...

Shum, Matthew, Sun, Wei, and Ye, Guangliang—Superstition and ‘‘lucky’’ apartments: Evidence from transaction-level data Using a sample of apartment transactions during 2004–2006 in Chengdu, China, we investigate the impact of superstitions in the Chinese real estate market. Numerology forms an important component of Chinese superstitious lore, with the numbers 8 and 6 signifying good luck, and ...

We investigate tilings of cubiculated regions with two simply connected floors by 2×1×1 bricks. More precisely, we study the flip connected component for such tilings, and provide an algebraic invariant that “almost” characterizes the flip connected components of such regions, in a sense that we discuss in the paper. We also introduce a new local move, the trit, which, together with the flip, c...

We analyze the e ects of a legally-binding price oor using Hotelling's model of locational competition. A moderate priceoor destroys the maximal di erentiation equilibrium of d'Aspremont et. al., by allowing rms to compete more aggressively for market share. Minimum di erentiation results, with lower equilibrium prices. A low price oor results in mulitiple equilibria both minimum and maximum di...

Financial trading has been described as ‘‘technological warfare’’. Whether or not you believe the metaphor, trading systems certainly involve a tremendous need for highly reliable, interruption free, real-time data. Real-time, in this case, means presented accurately and without delay. Current practice of medium to large trading floors often involves Unix based workstations and significant atte...

To protect the non-structural components in critical facilities (such as hospitals), focusing in particular on the key sensitive components on the floor of a room, the combined solution of stiffening the structure and isolating the floor is proposed. One-story and three-story stiffened shear frames were considered as examples for the purpose of conducting different analyses. Models for each ana...

Voice conferencing is an essential block of any multimedia system used for collaborative work, as voice is shared by all participants. Floor control is mission-critical here and has been investigated by many to ensure fair resource sharing; yet fixing the number of floors has remained an open problem. A conferee (participant in a conference) can speak only after acquiring the floor. To allow im...

Several issues should be considered when assessing the feasibility of remediation following the detonation of a radiological dispersion device (e.g., dirty bomb) or improvised nuclear device in a large city. These issues include the levels and characteristics of the radioactive contamination, the availability of resources required for decontamination, and the planned future use of the city's st...