purpose: e is a commonly use letter for illiterates or those who could not read english to measure visual acuity. the e chart is the mainly used charts in iran. however, they do not have the standards. they are in different format, fixed for 6 meter test, with or without lighting, with unequal number of letters in each line and different contrasts. as a result, there is an essential need for a ...

BACKGROUND Different visual acuity chart can be targeted to evaluate the visual function of patients with different eye diseases. We conducted a comparative analysis of the digital logarithm of the minimum angle of resolution (LogMAR) vision chart and the standard logarithmic vision chart for the measurement of visual acuity after retinal detachment surgery. METHODS We used the digital LogMAR...

A known difficulty with using the Clauser chart method to determine the friction velocity in wall bounded flows is that it assumes, a priori, a logarithmic law for the mean velocity profile. Using both experimental and DNS data in the literature, this note explicitly shows how friction velocities obtained using the Clauser chart method can potentially mask subtle Reynolds-number-dependent behav...

AIM To develop a customised, portable, cost-effective (logarithmic minimal angle resolution) LogMAR chart with adjustable illumination for use as a mass vision-screening device in the rural population. MATERIALS AND METHODS Visual acuity of 100 individuals was evaluated with a customised chart and compared with the standard Early Treatment Diabetic Retinopathy Study (ETDRS) chart and Snellen'...

Gairdner, D., and Pearson, J. (1971). Archives of Disease in Childhood, 46, 783. A growth chart for premature and other infants. The growth chart covers the period from 28 weeks of fetal life to age 2 years, and allows weight, length, and head circumference to be charted. The time scale is logarithmic, providing the convenience of an extended scale for the earlier months of life, and giving the...

to know the water quality characteristics of tehran subterranean canals, from 20 feb. 1978 to 23 sept. 1978, samples were taken from 23 of them by simple random sampling without replacement, and were analyzed according to the 14th edition of standards method for the examination of water and waste water 1975. arithmetic average concentration of water analyses of 23 subterranean canals were drawn...

Logarithmic CMOS image sensors encode a high dynamic range scene in a manner that roughly approximates human perception whereas linear sensors with equivalent quantization suffer from saturation or loss of detail. Moreover, the continuous response of logarithmic pixels permit high frame rates and random access, features that are useful in motion detection. This paper describes how to model, cal...