Wie schon vor einem Jahr wurde die aktuelle Konjunkturprognose (Anfang 1999) in das RWI Klassifikationsschema eingeordnet. Danach liegt die wirtschaftliche Entwicklung des Zeitraums 1998-3 bis 2000-4 im Grenzbereich zwischen Aufschwung und oberem Wendepunkt. Vor einem Jahr war die damalige...

We consider the triangle test with replications, i.e. each assessor is asked repeatedly. A commonly used test statistic for this situation is the sum of all correct assessments, summed over all assessors. Several authors (e.g. o’Mahony, 1982, Brockhoff and Schlich, 1998) argue that the...

In the common nonparametric regression model y(i) = g(ti) + a (ti) ei , i=1….,n with i.i.d - noise and nonrepeatable design points ti we consider the problem of choosing an optimal design for the estimation of the regression function g. A minimax approach is adopted which searches for designs...

Do active vertical mass movements occur within a population of phototropic bacteria in the meromictic Lake Cadagno. An experiment was conducted in vivo to record vertical profiles of the parameters turbidity and temperature in a spatial resolution of 30 cm repeatedly over time. After eliminating...

This paper applies linear discriminant analysis to classify West German business cycles from 1955 to 1994 into a four phase scheme (upswing, downswing, and upper/lower turning point phases). It describes the scheme as well as the selection of the classifying variables, and presents...

The minimum number of misclassifications achievable with affine hyper_ planes on a given set of labeled points is a key quantity in both statistics and computational learning theory. However, determining this quantity exactly is essentially NP_hard_ cf_ Höfgen, Simon and van Horn (1995.) Hence,...

In the common polynomial regression of degree m we determine the design which maximizes the minimum of the D-efficiency in the model of degree m and the D-efficiencies in the models of degree m – j,…, m + k (j, k 0 given). The resulting designs allow an efficient estimation of the...

In this paper the optimal design problem for the estimation of the individual coefficients in a polynomial regression on an arbitrary interval [a, b] (- inf. a b inf) is considered. Recently, Sahm (2000) demonstrated that the optimal design is one of four types depending on the symmetry...

In this note we consider the D-optimal design problem for the heteroscedastic polynomial regression model. Karlin and Studden (1966a) found explicit solutions for three types of efficiency functions. We introduce two ‘new’ functions to model the heteroscedastic structure, for which the...