Towards Machine Wald

The past century has seen a steady increase in the need of estimating and predicting complex systems and making (possibly critical) decisions with limited information. Although computers have made possible the numerical evaluation of sophisticated statistical models, these models are still designed \emph{by humans} because there is currently no known recipe or algorithm for dividing the design of a statistical model into a sequence of arithmetic operations. Indeed enabling computers to \emph{think} as \emph{humans} have the ability to do when faced with uncertainty is challenging in several major ways: (1) Finding optimal statistical models remains to be formulated as a well posed problem when information on the system of interest is incomplete and comes in the form of a complex combination of sample data, partial knowledge of constitutive relations and a limited description of the distribution of input random variables. (2) The space of admissible scenarios along with the space of relevant information, assumptions, and/or beliefs, tend to be infinite dimensional, whereas calculus on a computer is necessarily discrete and finite. With this purpose, this paper explores the foundations of a rigorous framework for the scientific computation of optimal statistical estimators/models and reviews their connections with Decision Theory, Machine Learning, Bayesian Inference, Stochastic Optimization, Robust Optimization, Optimal Uncertainty Quantification and Information Based Complexity.Comment: 37 page

Amoeba Techniques for Shape and Texture Analysis

Morphological amoebas are image-adaptive structuring elements for morphological and other local image filters introduced by Lerallut et al. Their construction is based on combining spatial distance with contrast information into an image-dependent metric. Amoeba filters show interesting parallels to image filtering methods based on partial differential equations (PDEs), which can be confirmed by asymptotic equivalence results. In computing amoebas, graph structures are generated that hold information about local image texture. This paper reviews and summarises the work of the author and his coauthors on morphological amoebas, particularly their relations to PDE filters and texture analysis. It presents some extensions and points out directions for future investigation on the subject.Comment: 38 pages, 19 figures v2: minor corrections and rephrasing, Section 5 (pre-smoothing) extende

EFEITO DO CARBARYL SOBRE O 'RUSSETING' DA MAÇÃ (MALUS DOMESTICA BORKH.), CULTIVARES 'GALA', 'FUJI' E 'GOLDEN DELICIOUS' EFFECT OF CARBARYL ON RUSSETING OF APPLE (Malus domestica Borkh.), CULTIVARS 'GALA', 'FUJI' AND 'GOLDEN DELICIOUS'

O "russeting" da maçã caracteriza-se por uma camada de cortiça formada entre as células da epiderme e que dá um aspecto de rugosidade à superfície do fruto, depreciando-o para a comercialização. O raleio de frutos é uma prática cultural bastante difundida entre os produtores de maçã. Pode ser efetuada manualmente, quimicamente ou pela associação de ambos. Dentre os produtos mais usados para raleio químico, estão o ácido naftaleno acético (ANA) e o carbaryl, um inseticida carbamato, conhecido comercialmente como Sevinâ. Há duas formulações de carbaryl no mercado brasileiro, mas não existem dados de pesquisa suficientes que permitam escolher a formulação mais adequada. Há citações de que o carbaryl pode causar "russeting" em maçãs. O objetivo deste trabalho foi testar as duas formulações de carbaryl existentes no mercado, quanto ao seu efeito sobre o "russeting" nas maçãs. Os experimentos foram conduzidos em Fraiburgo e em Caçador, Santa Catarina, Brasil. Foram avaliadas duas concentrações, 500 ppm e 1.500 ppm de carbaryl. Foram testadas duas formulações, uma em pó-molhável com 85% de i.a. e outra em suspensão concentrada com 48% de i.a. Como a incidência de "russeting" varia entre cultivares, testou-se em 'Gala', 'Fuji' e 'Golden Delicious', que são as três mais importantes no mercado brasileiro. Os resultados mostraram que: 1) A ocorrência de "russeting" para as três cultivares foi maior em Fraiburgo do que em Caçador; 2) O carbaryl, na formulação solução concentrada, causou mais "russeting" em 'Golden Delicious', em Caçador, indicando que o seu uso deve ser evitado para essa cultivar, dando-se preferência à formulação pó-molhável; 3)Tanto a formulação quanto a concentração de carbaryl não afetaram a incidência de "russeting" nas cultivares 'Gala' e 'Fuji' nos dois locais.<br>Russeting is characterized by the development of a cork layer among the epidermal cells giving an aspect of rugosity to the fruit surface, reducing its marketability. Fruit thinning is a technique widely used by apple growers. It can be done by hand or by using chemical thinning or by both, chemical and hand thinning. Among the most used chemical for thinning are naphthaleneacetic acid (NAA) and the insecticide carbaryl, commonly known as Sevinâ. In the Brazilian market there are two formulations of carbaryl: wetted powder and flowable solution. None of them are registered as chemical thinning for apple in Brazil. However there is not enough official research data in Brazil in this area that could support the best choice as far as russeting on the fruit is concerned. Some authors say that carbaryl may cause russeting on apples. This trial aimed to evaluate the two carbaryl formulations comparing its effect concerned to russeting. The experiments were carried out in two areas: Fraiburgo and Caçador, Santa Catarina State, Brazil. Two concentrations: 500 ppm and 1.500 ppm of each formulation were tested. One of the formulations was a wetted powder with 85% of a.i., the other was a flowable solution with 48% of a.i. As the incidence of russeting on apple may vary according to cultivar, the experiments were carried out on 'Gala', 'Fuji' and 'Golden Delicious'. It was concluded that: 1) Fraiburgo climactic conditions were much more favorable to russeting than those in Caçador; 2) carbaryl did not cause russeting on 'Gala' and 'Fuji' in both locations; 3) Carbaryl as flowable solution caused more russeting in 'Golden Delicious' at Caçador, so this formulation should not be recommended for this cultivar