21,192 research outputs found
Literature review of some selected types of results and statistical analyses of total-ozone data
The depletion of ozone in the stratosphere is examined, and causes for the depletion are cited. Ground station and satellite measurements of ozone, which are taken on a worldwide basis, are discussed. Instruments used in ozone measurement are discussed, such as the Dobson spectrophotometer, which is credited with providing the longest and most extensive series of observations for ground based observation of stratospheric ozone. Other ground based instruments used to measure ozone are also discussed. The statistical differences of ground based measurements of ozone from these different instruments are compared to each other, and to satellite measurements. Mathematical methods (i.e., trend analysis or linear regression analysis) of analyzing the variability of ozone concentration with respect to time and lattitude are described. Various time series models which can be employed in accounting for ozone concentration variability are examined
Statistical support for the ATL program
Statistical experimental designs are presented for various numbers of organisms and agar solutions pertinent to the experiment, ""colony growth in zero gravity''. Missions lasting 7 and 30 days are considered. For the designs listed, the statistical analysis of the observations obtained on the space shuttle are outlined
Lunar contour mapping system /lucom/ final report, 5 aug. 1964 - 18 mar. 1965
Radar sensor system for acquisition of lunar surface data - Lunar contour mapping syste
The economic value of viewing migratory shorebirds on the Delaware Bay: An application of the single site travel cost model using on-site data
We estimated a count data model of recreation demand using data from an on-site survey of recreational birders who had visited southern Delaware during the monthālong annual horseshoe crab/shorebird spring migration in 2008. We analyzed daytrips only. Our estimates from the models ranged from 142/trip/household or about 582/season/household (2008$). The variation was due to differences in the value of time. The average household size was 1.66. We found that the valuation results were sensitive to the inclusion of covariates in the model. Our results are useful for damage assessments and benefitācost analyses where birdwatching is affected.recreational birding, economic value, shorebird migration, onsite sampling, endogenous stratification
Measuring the Recreational Use Value of Migratory Shorebirds on the Delaware Bay
In this article we estimate the recreational use value of household trips to view shorebirds during the annual horseshoe crab/shorebird migration on the Delaware Bay. We use contingent valuation to estimate the value of day and overnight trips separately and use a discrete choice question followed by a payment-card question to generate our valuation data. Our best estimates for the value of a day trip are about 90/household and for an overnight trip about 425/household (200863/trip/person to $442/trip/person. These studies vary in method and specific birding populations studied and mix day and overnight trips.Contingent valuation, discrete choice, bird watching, use value, Environmental Economics and Policy, Public Economics, Research Methods/ Statistical Methods, Q5,
"The Economic Value of Viewing Migratory Shorebirds on the Delaware Bay: An Application of the Single Site Travel Cost Model Using On-Site Data"
Using data from an on-site survey of recreational birders in southern Delaware during the annual horseshoe crab/shorebird spring migration, we estimated four truncated count data models of recreation demand accounting for endogenous stratification due to onsite sampling. We analyzed day-trips only and conducted sensitivity analysis on measurement of the value of time and inclusion of covariates. Our estimates from the models using all covariates were in the range of 178/trip/household (2008$). The variation is due to differences in the value of time. The average household size is 1.66.Travel-Cost Model, Shorebirds, Valuation
A study of the feasibility of statistical analysis of airport performance simulation
The feasibility of conducting a statistical analysis of simulation experiments to study airport capacity is investigated. First, the form of the distribution of airport capacity is studied. Since the distribution is non-Gaussian, it is important to determine the effect of this distribution on standard analysis of variance techniques and power calculations. Next, power computations are made in order to determine how economic simulation experiments would be if they are designed to detect capacity changes from condition to condition. Many of the conclusions drawn are results of Monte-Carlo techniques
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