315 resultados para estimation des provisions
em Queensland University of Technology - ePrints Archive
Resumo:
How to Improve Pupils' Literacy? A Cost-Effectiveness Analysis of the Action Lecture This article presents a cost-effectiveness analysis of an innovative teaching method run in some nursery and primary schools in Paris. This project, named Action Lecture, is designed to improve pupils' abilities and taste on literacy. We report the results of an evaluation of this program. We describe the experimental protocol that was built to estimate the program's impact on several types of indicators (academic abilities, attitude toward reading, school life) by comparing the evolution of treatment schools and control schools. Data were processed following a Differences-in-Differences (DID) method. Then we use the estimation of the impact on academic achievement to conduct a cost-effectiveness analysis and take a reduction of the class size program as a benchmark. The results are positive for the Action Lecture program both in terms of impact's evaluation and in terms of cost-effectiveness ratio.
Resumo:
We consider the development of statistical models for prediction of constituent concentration of riverine pollutants, which is a key step in load estimation from frequent flow rate data and less frequently collected concentration data. We consider how to capture the impacts of past flow patterns via the average discounted flow (ADF) which discounts the past flux based on the time lapsed - more recent fluxes are given more weight. However, the effectiveness of ADF depends critically on the choice of the discount factor which reflects the unknown environmental cumulating process of the concentration compounds. We propose to choose the discount factor by maximizing the adjusted R-2 values or the Nash-Sutcliffe model efficiency coefficient. The R2 values are also adjusted to take account of the number of parameters in the model fit. The resulting optimal discount factor can be interpreted as a measure of constituent exhaustion rate during flood events. To evaluate the performance of the proposed regression estimators, we examine two different sampling scenarios by resampling fortnightly and opportunistically from two real daily datasets, which come from two United States Geological Survey (USGS) gaging stations located in Des Plaines River and Illinois River basin. The generalized rating-curve approach produces biased estimates of the total sediment loads by -30% to 83%, whereas the new approaches produce relatively much lower biases, ranging from -24% to 35%. This substantial improvement in the estimates of the total load is due to the fact that predictability of concentration is greatly improved by the additional predictors.