Showing 91 - 100 of 652
Persistent link: https://www.econbiz.de/10009216857
When a process is dominated by few important frequencies the observations of this process can be modelled by a harmonic process (Bloomfield (2000)). If the amplitudes of these dominating frequencies vary over time their dominance may not be apparent during the whole process. To discriminate...
Persistent link: https://www.econbiz.de/10009216858
The aim of this paper is to extract mathematically talented students out of a group of arbitrary high school students. We do this by applying a stepwise discriminant analysis modified for ordinal data to the results of German high school students at the international mathematics competition...
Persistent link: https://www.econbiz.de/10009216859
In this paper we study statistical inference for certain inverse problems. We go beyond mere estimation purposes and review and develop the construction of confidence intervals and confidence bands in some inverse problems, including deconvolution and the backward heat equation. Further, we...
Persistent link: https://www.econbiz.de/10009216860
Persistent link: https://www.econbiz.de/10009216862
In this paper a new test for the parametric form of the variance function in the common nonparametric regression model is proposed which is applicable under very weak smoothness assumptions. The new test is based on an empirical process formed from pseudo residuals, for which weak convergence to...
Persistent link: https://www.econbiz.de/10009216863
Data sets from car insurance companies often have a high-dimensional complex dependency structure. The use of classical statistical methods such as generalized linear models or Tweedie?s compound Poisson model can yield problems in this case. Christmann (2004) proposed a general approach to...
Persistent link: https://www.econbiz.de/10009216864
Recently, Dette, Neumeyer and Pilz (2005a) proposed a new monotone estimator for strictly increasing nonparametric regression functions and proved asymptotic normality. We explain two modifications of their method that can be used to obtain monotone versions of any nonparametric function...
Persistent link: https://www.econbiz.de/10009216865
Most credit portfolio models exclusively calculate the loss distribution for a portfolio of performing counterparts. Conservative default definitions cause considerable insecurity about the loss for a long time after the default. We present three approaches to account for defaulted counterparts...
Persistent link: https://www.econbiz.de/10009216866
N-Acetyltransferase 2 (NAT2) genotyping may result in a considerable percentage in several ambiguous allele combinations. PHASE 2.1 is a statistical program which is designed to estimate the probability of different allele combinations. We have investigated haplotypes of 2088 subjects genotyped...
Persistent link: https://www.econbiz.de/10009216867