Spectral density of random signals corrupted by multiplicative noise

A simple method of evaluating the spectral density of stationary random signals corrupted by multiplicative noise is presented. It is assumed that the multiplicative noise is also stationary, and that it is statistically independent of the signal.     

A formative and summative evaluation model for special educational programs

During the past two decades the problems of recruiting minority students into careers in the health fields have been addressed by many educators and various special study groups. Recent efforts by schools of medicine and allied health sciences to find viable solutions to the problem have facilitated implementation of career exploration and study-skills programs. Although the focus and sophistication of evaluation designs vary substantially among educational programs of this type, all share some common problems. The positions taken by the authors is that evaluation, both during and at the end of a program, is an essential aspect of the program and that the use of a systematic evaluation model is central to this effort. Data are presented which illustrate the utility of a systematic evaluation model when applied in a realistic test situation (an operational program for minority students). Several advantages of using this model are discussed.     

Picture perception and monocular vision: a reply to Hagen

It is argued that M. A. Hagen's (see record 1975-00215-001) review of picture perception contains a number of inaccuracies involving the nature of higher order variables in perception, the demonstration of visual compensation, the manipulation of relative size information, the postulation of an ability to discriminate the correctness of viewing point, and the existence of ambiguity in monocular perception. It is suggested that such errors are the result of a misunderstanding of the formal basis of J. J. Gibson's (1950, 1966) perceptual theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the layer sequence and morphology in solid-state displacement reactions

In displacement reactions of the type pA+B_qXqB+A_pX, two main forms of the layer sequence have been found in the reaction layer, namely, A/A_pX/B/B_qX and A/B/A_pX/B_qX. In this paper it is argued that the thermodynamics of the system, more specifically the dependence of the activity of element X on the mole ratio between the elements A and B, determines the initial layer sequence. Various morphological variants of the two basic types may develop because of the kinetics. The prediction of the layer sequence and morphology made on the basis of this theory has been verified on a number of oxidic and sulfidic systems. It is, however, pointed out that these predictions also can be applied to purely metallic ternary systems and to other types of reactions.     

Ordering of spectral factors and its application

In connection with the solution of matrix Wiener-Hopf equations, the need for the correct ordering of spectral factors is emphasised. Modifications to the method of augmented factors are presented to accommodate the reverse-ordering of spectral factors.