In this paper, we study the recognition complexity of discrete geometric 2gures (rectangles, squares, circles, ellipses) on a retina by diameter-limited and order-restricted perceptrons. We construct a diameter-limited recognition perceptron for the family of rectangles, beginning with local con2gurations, which is di6erent from the one shown by Minsky et al. (Perceptrons: An Introduction to Co...

The aim of this study is ultraviolet and infrared spectral characterization of eight new xanthine derivatives. Spectral analysis was performed using an Agilent 8453 Series spectrophotometer and a Tensor 27 Optics FT-IR spectrophotometer. The UV and IR spectra for xanthine derivatives were obtained and in addition, the wavelength maxima of absorption bands and characteristics have been established.

BACKGROUND AND OBJECTIVES This in vitro study compared the shade matching abilities of an intraoral spectrophotometer and the conventional visual method using two shade guides. The results of previous investigations between color perceived by human observers and color assessed by instruments have been inconclusive. The objectives were to determine accuracies and interrater agreement of both met...

INTRODUCTION Breastfeeding promotion is one of the most important strategies against infant mortality and to control child undernourishment. Despite policies and plans to promote and protect breastfeeding in Colombia, its practice is low and its duration is short. OBJECTIVE To propose an ecology framework to interpret and incorporate contextual, interpersonal, and individual factors associate...

AN INTRODUCTION TO THE PLANT SCIENCES By WILLIAM C. DARRAH, Tutor in the Department of Biology and Research Curator in the Botanical Museum, Harvard University. This book offers a concise, humanistic account, of the nature of the plant kingdom. It is intended for use by students in a half-year or one-semester course in botany or plant biology. Emphasis is placed on these four recent development...

Corresponding Author: Dr. Gabriele Corciolani, Via Derna 4, 58100 Grosseto (Italy) E-mail: [email protected]; Tel/Fax: +39056425384 Abstract Objectives: The aim of this study was to evaluate the repeatability of readings with a clinical spectrophotometer in comparison with a laboratory one. Materials and Methods: A stand alone clinical spectrophotometer (Easyshade, Vita) and a labor...