For FRF based model updating procedures, the selection of updating frequencies and the choice of a damping approach are important factors to obtain reliable updating resuns. This paper discusses the selection of the updating frequencies and shows that damping approaches like proportional, structural or modal damping are not satisfactory for model updating purposes.

The primary interest of this paper is in out-of-sample forecasting for the U.S. monthly unemployment rate. Several linear unobserved components models are fitted and their comparative forecasting accuracy is assessed by means of and extensive rolling-origin procedure using a test period that covers the last two decades. An attempt is made to link forecasting performance to the time domain prope...

The frequency response masking technique is an e cient method to realize sharp 1-D lters. This technique can synthesize sharp 1-D lters with a considerably lower complexity when compared to direct-form implementations. In this paper, we extend the frequency response masking technique to the design of 2-D diamond-shaped lters. The design procedure as well as the prototype and masking lters speci...

In a previous paper we introduced a general transformation on sources and one on items in an arbitrary information production process (IPP). In this paper we investigate the influence of these transformations on the h-index and on the g-index. General formulae that describe this influence are presented. These are applied to the case that the size-frequency function is Lotkaian (i.e. is a decrea...

We measure the sharpness of natural (complex) images using Gaussian models. We first locate lines and edges in the image. We apply Gaussian derivatives at different scales to the lines and edges. This yields a response function, to which we can fit the response function of model lines and edges. We can thus estimate the width and amplitude of the line or edge. As measure of the sharpness we pro...

We prove sharp upper and lower bounds for the nodal length of Steklov eigenfunctions on real-analytic Riemannian surfaces with boundary. The argument involves frequency function methods for harmonic functions in the interior of the surface as well as the construction of exponentially accurate approximations for the Steklov eigenfunctions near the boundary.

1995 iii Dedication For those with enough patience to read it. Displacement of the basilar membrane in response to a sinusoid at 4 stages in its propagation (after von Bekesy, [1960]). .......10 Figure 2.2 Frequency response of neural fibers along a cat's basilar mem-Figure 2.3 Measured at 18 kHz center frequencies: A) Basilar motion in response to constant level inputs of varying frequency (af...

This paper presents a novel equivalent, which is suitable for simulation of inertial and primary frequency control effects. In the model reduction procedure, dynamic power injectors are used to replace the external system and to mimic its dynamic behavior. The parameters of the equivalents are tuned with a simple approach presented in this paper. The effectiveness of the proposed method is demo...