Revalorizar la agricultura y la alimentación

Si hubiera nacido diccionario sería un diccionario ndignado. La visión capitalista que todo lo inunda ha dejado mis pobres páginas y sus contenidos totalmente maltrechos y corrompidos. Pienso en una de mis palabras: revalorizar. «Este terreno se ha revalorizado», «los índices bursátiles se han revalorizado», etc. son frases donde su uso es frecuente, demostrando que lo que importa es 'incrementar el valor', propio de los deseos lucrativos instalados en nuestra sociedad. Y parece que no se estime que revalorizar es también cambiar de valores, o volver a pensarlos.Si esta crisis actual no es ni más ni menos que una crisis de valores, salir de la crisis será revalorizar nuestros principios. También nuestro sistema agroalimentario, lo que comemos y quién y cómo lo produce, está en crisis. En la medida que los valores capitalistas han profundizado en él, más personas pasan hambre, más personas pierden su medio de vida y más castigado, caliente y enfermo está el Planeta. Urge pues plantearse una revalorización, es decir, definir otros valores que orienten su funcionamiento

Partial match queries in relaxed K-dt trees

The study of partial match queries on random hierarchical multidimensional data structures dates back to Ph. Flajolet and C. Puech’s 1986 seminal paper on partial match retrieval. It was not until recently that fixed (as opposed to random) partial match queries were studied for random relaxed K-d trees, random standard K-d trees, and random 2-dimensional quad trees. Based on those results it seemed natural to classify the general form of the cost of fixed partial match queries into two families: that of either random hierarchical structures or perfectly balanced structures, as conjectured by Duch, Lau and Martínez (On the Cost of Fixed Partial Queries in K-d trees Algorithmica, 75(4):684–723, 2016). Here we show that the conjecture just mentioned does not hold by introducing relaxed K-dt trees and providing the average-case analysis for random partial match queries as well as some advances on the average-case analysis for fixed partial match queries on them. In fact this cost –for fixed partial match queries– does not follow the conjectured forms.Peer ReviewedPostprint (author's final draft

Fixed Partial Match Queries in Quadtrees

Several recent papers in the literature have addressed the analysis of the cost P_{n,q} of partial match search for a given fixed query q - that has s out of K specified coordinates - in different multidimensional data structures. Indeed, detailed asymptotic estimates for the main term in the expected cost P_{n,q} = E {P_{n,q}} in standard and relaxed K-d trees are known (for any dimension K and any number s of specified coordinates), as well as stronger distributional results on P_{n,q} for standard 2-d trees and 2-dimensional quadtrees. In this work we derive a precise asymptotic estimate for the main order term of P_{n,q} in quadtrees, for any values of K and s, 0 infty exists, where alpha is the exponent of n in the expected cost of a random partial match query with s specified coordinates in a random K-dimensional quadtree

On the cost of fixed partial match queries in K-d trees

The final publication is available at Springer via http://dx.doi.org/10.1007/s00453-015-0097-4Partial match queries constitute the most basic type of associative queries in multidimensional data structures such as K-d trees or quadtrees. Given a query q=(q0,…,qK-1) where s of the coordinates are specified and K-s are left unspecified (qi=*), a partial match search returns the subset of data points x=(x0,…,xK-1) in the data structure that match the given query, that is, the data points such that xi=qi whenever qi¿*. There exists a wealth of results about the cost of partial match searches in many different multidimensional data structures, but most of these results deal with random queries. Only recently a few papers have begun to investigate the cost of partial match queries with a fixed query q. This paper represents a new contribution in this direction, giving a detailed asymptotic estimate of the expected cost Pn,q for a given fixed query q. From previous results on the cost of partial matches with a fixed query and the ones presented here, a deeper understanding is emerging, uncovering the following functional shape for Pn,q Pn,q=¿·(¿i:qi is specifiedqi(1-qi))a/2·na+l.o.t. (l.o.t. lower order terms, throughout this work) in many multidimensional data structures, which differ only in the exponent a and the constant ¿, both dependent on s and K, and, for some data structures, on the whole pattern of specified and unspecified coordinates in q as well. Although it is tempting to conjecture that this functional shape is “universal”, we have shown experimentally that it seems not to be true for a variant of K-d trees called squarish K-d trees.Peer ReviewedPostprint (author's final draft

Fixed partial match queries in quadtrees

Several recent papers in the literature have addressed the analysis of the cost P_{n,q} of partial match search for a given fixed query q - that has s out of K specified coordinates - in different multidimensional data structures. Indeed, detailed asymptotic estimates for the main term in the expected cost P_{n,q} = E {P_{n,q}} in standard and relaxed K-d trees are known (for any dimension K and any number s of specified coordinates), as well as stronger distributional results on P_{n,q} for standard 2-d trees and 2-dimensional quadtrees. In this work we derive a precise asymptotic estimate for the main order term of P_{n,q} in quadtrees, for any values of K and s, 0 infty exists, where alpha is the exponent of n in the expected cost of a random partial match query with s specified coordinates in a random K-dimensional quadtree.Peer ReviewedPostprint (published version

Alimentació

[p.4] Crisi? quina crisi?[p.8] El menjar com a mestre[p.17] Aprendre a desaprendre[p.21] Jo vull ser pagès[p.24] Per un canvi radical[p.32] Fam i obesitat, relacions i contradiccions[p.13] Alimentació i medicina[p.14] Educació del gust[p.20] Aprendre a l'hort?[p.27] "Quan mengis la fruita recorda't de qui la cultiva"[p.28] Universitats contra la fam[p.35] Diversitat alimentària a l'escola[p.36] Alimentació a escala humana[p.38] La dècada de l'educació per al desenvolupament sosteniblePeer Reviewe