We have developed a new technique to characterize the multi-line emission from molecular clouds using statistical sampling. Our method uses available extinction maps select relatively small sample of cloud positions that cover full range column densities in cloud, and can be observed with only modest investment telescope time. Here we present first results applying this Perseus nearby star-form...

We look at the benefits of using a kind of quasi-random numbers to obtain more accurate results for a given number of simulation runs. We explore a sampling method with enhanced independence in multidimensional simulations by combining the ideas of stratified sampling and Latin Hypercube sampling. We test the new sampling method by comparing it with traditional stratified sampling and Latin Hyp...

Estimates of erosion and sediment delivery have often relied on measurements from locations that were selected to be representative of particular terrain types. Such judgement samples are likely to overestimate or underestimate the mean of the quantity of interest. Probability sampling can eliminate the bias due to sample selection, and it permits the explicit expression of uncertainty with est...

The understanding of the behavioural aspects of a software system is an important enabler for many reverse engineering activities. The behaviour of software is typically represented in the form of execution traces. Traces, however, can be overwhelmingly large. To reduce their size, sampling techniques, especially the ones based on random sampling, have been extensively used. Random sampling, ho...

OBJECTIVES Providing high service quality is one of the main functions of health systems. Measuring service quality is the basic prerequisite for improving quality. The aim of this study was to evaluate the quality of service in teaching hospitals using importance-performance analysis matrix. METHODS A descriptive-analytic study was conducted through a cross-sectional method in six academic h...

Flow-stratified sampling is a new method for sampling water quality constituents such as suspended sediment to estimate loads. As with selection-at-list-time (SALT) and time-stratified sampling, flow-stratified sampling is a statistical method requiring random sampling, and yielding unbiased estimates of load and variance. It can be used to estimate event yields or to estimate mean concentratio...

Stratified random sampling at differential rates is commonly used in social science surveys to improve the chances of getting sufficiently large samples of subpopulations of interest. Multi-phase sampling is often used to further target desired populations. The variances of such samples can be estimated using jackknifing, which creates replicated values of the characteristic of interest as if o...