排序方式: 共有8条查询结果,搜索用时 758 毫秒
1
1.
Silvano?BordignonEmail author Carlo?Gaetan Francesco?Lisi 《Statistical Methods and Applications》2002,11(2):227-245
One of the main concerns in air pollution is excessive tropospheric ozone concentration. The aim of this work is to develop
statistical models giving shortterm forecasts of future ground-level ozone concentrations. Since there are few physical insights
about the dynamic relationship between ozone, precursor emissions and/or meteorological factors, a nonparametric and nonlinear
approach seems promising in order to specify the forecast models. First, we apply four nonparametric procedures to forecast
daily maximum 1-hour and maximum 8-hour averages of ozone concentrations in an urban area. Then, in order to improve the forecast
performances, we combine the time series of the forecasts. This idea seems to give encouraging results.
This work was supported by a MURST grant. The authors would like to thank two anonymous referees for their helpful comments. 相似文献
2.
ARFIMA (p, d, q) processes. In particular we obtain the (asymptotic) mean square prediction error when the parameters of the process are
either known or estimated in the cases both of correct and misspecified model. Some Monte Carlo experiments confirm the validity
of the asymptotic results.
Received: August 6, 1999; revised version: June 26, 2000 相似文献
3.
Models and Bounds for Two-Dimensional Level Packing Problems 总被引:2,自引:0,他引:2
We consider two-dimensional bin packing and strip packing problems where the items have to be packed by levels. We introduce new mathematical models involving a polynomial number of variables and constraints, and show that their LP relaxations dominate the standard area relaxations. We then propose new (combinatorial) bounds that can be computed in O(nlog n) time. We show that they dominate the other bounds, and establish their absolute worst-case behavior. The quality of models and bounds is evaluated through extensive computational experiments. 相似文献
4.
5.
6.
7.
The three-partition problem is one of the most famous strongly NP-complete combinatorial problems. We introduce properties which, in many cases, can allow either a quick solution of an instance or a reduction of its size. The average effectiveness of the properties proposed is tested through computational experiments. 相似文献
8.
Process capability indices (PCIs) have been widely used in manufacturing industries to previde a quantitative measure of process
potential and performance. While some efforts have been dedicated in the literature to the statistical properties of PCIs
estimators, scarce attention has been given to the evaluation of these properties when sample data are affected by measurement
errors. In this work we deal with the problem of measurement errors effects on the performance of PCIs. The analysis is illustrated
with reference toC
p
, i.e. the simplest and most common measure suggested to evaluate process capability.
The authors would like to thank two anonymous referees for their comments and suggestion that were useful in the preparation
and improvement of this paper. This work was partially supported by a MURST research grant. 相似文献
1