ARE FUZZY SYSTEMS UNIVERSAL APPROXIMATORS?

Abstract

This paper is a critical reflection on various results in lileralure claiming that fuzzy systems are universal approximators. For this purpose the most specific features of fuzzy systems are outlined and it is discussed to which extent they are incorporated in the formal definition of a Tuzzy system in literature. It is argued that fuzzy systems can only be universal approximators in a rather reduced sense where some crucial features are neglected. The goal is to give an impulse to investigate more adequate mathematical concepts of a fuzzy system thai also take into account such features as transparency and linguistic interpretability.     

Bioavailability for Rats of Vitamin E from Fortified Breakfast Cereals

Bioavailability of vitamin E in three fortified breakfast cereals and dose-response relationships among dietary vitamin E and selected biochemical indices were investigated using a rat depletion-repletion model. Response criteria included concentrations of α-tocopherol in plasma, red blood cells, liver, heart, and adipose tissue, and plasma pyruvate kinase activity. Bioavailability of vitamin E in whole grain cereal and corn flakes was generally comparable to that of the tocopheryl acetate standard. Bioavailability of vitamin E in bran flakes was lower than that of the standard based on four of the criteria. A food matrix effect in bran flakes resulted in the lower bioavailability.     

LARGE WIND TURBINES: A EUROPEAN COORDINATED DEVELOPMENT PROGRAMME

At the present time, the commercial use of wind energy for electricity production is based on series produced wind energy turbines with power ratings up to approximately 500 kW. In a good wind regime turbines of this kind can achieve energy production costs near to conventional generating costs. Very large wind energy conveners in the megawatt range have been under development for about 15 years, but as yet their commercial contribution is small.

The European Commission has taken a coordinated initiative to support the development of large wind turbines in the Megawatt power range. In the R&D programmes JOULE and THERMIE a variety of projects are being developed and demonstrated. The aim is the availability of economic large wind turbines for commercial application.     

Teaching Computational Abstract Algebra

We report on the contents and pedagogy of a course in abstract algebra that was taught with the aid of educational software developed within the Mathematica system. We describe the topics covered and the didactical use of the corresponding Mathematica packages, as well as draw conclusions for future such courses from the students' comments and our own experience.     

DYNAMIC CHARACTER OF CRITERIA: ORGANIZATION CHANGE.

PREVIOUS THOUGHT AND RESEARCH ON CRITERION DEVELOPMENT EMPHASIZE: MEASUREMENT PROBLEMS RELATED TO SCALING AND ANALYSIS, PROBLEMS CREATED BY THE SPONSOR, VALUES OF THE RESEARCHER, ASPECTS OF DERIVING A COMPOSITE CRITERION, AND THE DYNAMIC CHARACTER OF JOB REQUIREMENTS RELATED TO INCUMBENT LEARNING. THERE IS AN ADDITIONAL VARIABLE(S) TO BE CONSIDERED, ORGANIZATION CHANGE AND THE EFFECT OF CHANGING NEEDS ON THE NATURE OF THE CRITERIA OF INDIVIDUAL JOBS. JOB DUTIES MAY REMAIN STATIC UNDER THESE CIRCUMSTANCES, ONLY THE RELEVANCE OF PERFORMANCE CHANGES. (17 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grain-Boundary Characteristics and Their Influence on the Electrical Resistance of Barium Titanate Ceramics

The integral and spectral cathodoluminescence (CL) properties of grain-boundary zones in positive-temperature-coefficient-type barium titanate ceramics were investigated with respect to typical sintering parameters in the spectral range 300 to 1800 nm at room temperature. Spatially resolved CL micrographs for the wavelength range 300 to 850 nm show dark grain-boundary zones and light grain interiors. Corresponding micrographs for the infrared wavelength range 800 to 1800 nm show just the opposite CL contrast. The CL properties of the grain-boundary zone can be correlated to doubly ionized barium vacancies. Therefore, grain-boundary zones which are visible in integral CL images of both wavelength ranges represent the theoretically predicted grain-boundary zone of high barium vacancy concentrations. The width of these grain-boundary zones varies characteristically with sintering time and cooling rate. Additional measurements of the electrical conductivity of the specimens confirmed the theoretically assumed correlation between grain-boundary-zone width and electrical resistance of the samples.     

A MARKOV MODEL FOR CORRELATED LAND MOBILE SATELLITE CHANNELS

Some of the planned new satellite communication systems will use satellite diversity, i.e. simultaneous transmission via two or more satellites, in order to enhance the quality of service. Starting from two-state Markov models for two separate land mobile satellite channels, a combined model for two channels is developed, which takes into account their statistical interdependence. The parameters of this model as well as the resulting service quality are analytically derived; they depend on the statistics of the separate channels and on their correlation coefficient. Numerical examples for the unavailability of service illustrate the influence of the correlation coefficient on the benefit of satellite diversity and give some insight into the possible range of improvement.     

VALIDITY OF THE JOB-CONCEPT INTERVIEW IN AN INDUSTRIAL SETTING.

INTERVIEWS BY PSYCHOLOGISTS WERE USED TO PREDICT EMPLOYEE ATTITUDES AND JOB PERFORMANCE. CORRELATIONS WERE COMPUTED BETWEEN THE PSYCHOLOGIST'S PREDICTIONS, EMPLOYEE RATINGS OF THEIR JOB ATTITUDES, AND SUPERVISOR RATINGS OF EMPLOYEE JOB PERFORMANCE. THE PSYCHOLOGISTS WERE MOST ACCURATE IN PREDICTING EMPLOYEE ATTITUDES TOWARD ADVANCEMENT AND GENERAL MORALE, BUT LEAST ACCURATE IN PREDICTING EMPLOYEE ATTITUDES TOWARD SUPERVISION AND REWARDS. THEY WERE UNABLE TO PREDICT EMPLOYEE PERFORMANCE AS RATED BY THE SUPERVISORS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)