The demand function for vaccines against typhoid fever was estimated using stated preference data collected from a random sample of 1065 households in Hue, Vietnam, in 2002. These are the first estimates of private willingness-to-pay (WTP) and demand functions for typhoid vaccines in a developing country. Mean respondent WTP for a single typhoid fever vaccine ranged from USD 2.30 to USD 4.80. M...

Hue discrimination, spectral sensitivity, and mathematical models of both are presented for a rhesus monkey which was exposed to intense green light. One of the monkey's eyes was blue-blinded in a previous experimental procedure and the other was color normal. The results of green light exposure showed a loss of sensitivity on both measures, with greater loss in the blue-blinded eye. Although t...

We present an optimization technique to find hue constant RGB sensors. The hue representation is based on a log RGB opponent color space that is invariant to brightness and gamma. While modeling the visual response did not derive the opponent space, the hue definition is similar to the ones found in CIE Lab and IPT. Finding hue constant RGB sensors through this optimization might be applicable ...

Each hue is believed to be made up of the four component hues (yellow, blue, red, and green). A hue consisting of just one component hue is called unitary (or unique). A new technique--partial hue-matching--has been used to reveal the component and unitary hues for a sample of 32 Munsell papers, which were illuminated by neutral, yellow, blue, green, and red lights and assessed by four normal t...

Naive observers viewed a sequence of colored Mondrian patterns, simulated on a color monitor. Each pattern was presented twice in succession, first under one daylight illuminant with a correlated color temperature of either 16,000 or 4000 K and then under the other, to test for color constancy. The observers compared the central square of the pattern across illuminants, either rating it for sam...

This study examines the equivalence of the City University color vision test (CUT) to the Farnsworth Munsell D-15 (D-15). This information is important because a number of occupations require individuals to pass either the D-15 of the CUT. Using two or more major crossings on the D-15 as failure, our results indicate that agreement between tests can be improved if the failing criterion for the ...