DD Plots and Prediction Regions

2017 ◽  
pp. 139-188
Author(s):  
David J. Olive
Keyword(s):  
Author(s):  
Maria Lucia Parrella ◽  
Giuseppina Albano ◽  
Cira Perna ◽  
Michele La Rocca

AbstractMissing data reconstruction is a critical step in the analysis and mining of spatio-temporal data. However, few studies comprehensively consider missing data patterns, sample selection and spatio-temporal relationships. To take into account the uncertainty in the point forecast, some prediction intervals may be of interest. In particular, for (possibly long) missing sequences of consecutive time points, joint prediction regions are desirable. In this paper we propose a bootstrap resampling scheme to construct joint prediction regions that approximately contain missing paths of a time components in a spatio-temporal framework, with global probability $$1-\alpha $$ 1 - α . In many applications, considering the coverage of the whole missing sample-path might appear too restrictive. To perceive more informative inference, we also derive smaller joint prediction regions that only contain all elements of missing paths up to a small number k of them with probability $$1-\alpha $$ 1 - α . A simulation experiment is performed to validate the empirical performance of the proposed joint bootstrap prediction and to compare it with some alternative procedures based on a simple nominal coverage correction, loosely inspired by the Bonferroni approach, which are expected to work well standard scenarios.


Author(s):  
Elart von Collani ◽  
Klaus Dräger
Keyword(s):  

2016 ◽  
Vol 59 (3) ◽  
pp. 913-931 ◽  
Author(s):  
David J. Olive
Keyword(s):  

2014 ◽  
Vol 54 (10) ◽  
pp. 1757 ◽  
Author(s):  
S. R. O. Williams ◽  
P. J. Moate ◽  
M. H. Deighton ◽  
M. C. Hannah ◽  
W. J. Wales

Methane (CH4) emissions from dairy cows are technically difficult and expensive to measure. Recently, some researchers have found correlations between the concentrations of specific fatty acids in milk fat and the CH4 emissions from cows that could obviate the need for direct measurement. In this research, data on individual cow CH4 emissions and concentration of caprylic acid (C8:0) and total C18 fatty acids in milk were collated from eight experiments involving 27 forage-based diets and 246 Holstein-Friesian dairy cows. Linear regressions between CH4 and both C8:0 and total C18 in milk were produced for published data and used to calculate 95% prediction regions for a new observation. The proportion of observed methane emissions from eight experiments that fell outside the 95% prediction region was 27.6% for the C8:0 model and 26.3% for the total C18 model. Neither model predicted CH4 emission well with Lin’s coefficient of concordance of less than 0.4 and the Nash–Sutcliffe efficiency coefficient of approximately zero for both the C8:0 and total C18 models. In addition, general linear model analysis showed significant differences between experiments in their intercepts (P < 0.001) and slopes (P < 0.001). It is concluded that the relationships tested cannot be used to accurately predict CH4 emissions when cows are fed a wide range of diets.


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