Showing 481 - 490 of 654
We consider the problem of testing hypotheses regarding the covariance matrix of multivariate normal data, if the sample size s and dimension n satisfy lim [n,s→∞] n/s = y. Recently, several tests have been proposed in the case, where the sample size and dimension are of the same order, that...
Persistent link: https://www.econbiz.de/10009295187
The paper brings together methods from two disciplines: machine learning theory and robust statistics. Robustness properties of machine learning methods based on convex risk minimization are investigated for the problem of pattern recognition. Assumptions are given for the existence of the...
Persistent link: https://www.econbiz.de/10009295189
Wirtschaftsdaten als Objekte von Prognosen sind meist metrischer Natur: Arbeitslosenzahlen, Aktienkurse, Umsätze, Erlöse usw., alle sind quantitative Variable, bei denen sich Prognosen und realisierte Werte, wie auch konkurrierende Prognosen, leicht vergleichen lassen. Anders die Lage bei...
Persistent link: https://www.econbiz.de/10009295190
We investigate the possibility of exploiting partial correlation graphs for identifying interpretable latent variables underlying a multivariate time series. It is shown how the collapsibility and separation properties of partial correlation graphs can be used to understand the relation between...
Persistent link: https://www.econbiz.de/10009295191
In this paper we investigate locally E- and c-optimal designs for exponential regression models of the form _k i=1 ai exp(??ix). We establish a numerical method for the construction of efficient and locally optimal designs, which is based on two results. First we consider the limit ?i ? ? and...
Persistent link: https://www.econbiz.de/10009295192
Motivated by applications in statistical quality control and signal analysis, we propose a sequential detection procedure which is designed to detect structural changes, in particular jumps, immediately. This is achieved by modifying a median filter by appropriate kernel-based jump preserving...
Persistent link: https://www.econbiz.de/10009295193
The major focus of this paper is to determine whether the accuracy of German macroeconomic forecasts has improved over time. We examine 1-year-ahead forecasts of real GDP and inflation for 1967 to 2001 made by three major German forecasting groups and the OECD. We examine the accuracy of the...
Persistent link: https://www.econbiz.de/10009295194
For many problems of statistical inference in regression modelling, the Fisher information matrix depends on certain nuisance parameters which are unknown and which enter the model nonlinearly. A common strategy to deal with this problem within the context of design is to construct maximin...
Persistent link: https://www.econbiz.de/10009295195
Classical regression analysis is usually performed in two steps. In a first step an appropriate model is identified to describe the data generating process and in a second step statistical inference is performed in the identified model. An intuitively appealing approach to the design of...
Persistent link: https://www.econbiz.de/10009295196
In this paper we describe a computer intensive method to find the ridge parameter in a prediction oriented linear model. With the help of a factorial experimental design the method is tested and compared to a classical one.
Persistent link: https://www.econbiz.de/10009295197