Centros alfareros de la provincia

En número dedicado a: La provincia de Cácere

Drawing Feynman Diagrams with LaTeX and Metafont

Feynmf is a LaTeX package for easy drawing of professional quality Feynman diagrams with Metafont (or Metapost). Feynmf lays out most diagrams satisfactorily from the structure of the graph without any need for manual intervention. Nevertheless all the power of Metafont (or Metapost) is available for the most complicated cases.Comment: 19 pages, standard LaTeX2e with recent graphics and amstex packages, 45 figures (EPS), preformatted PostScript (300dpi) in ftp://crunch.ikp.physik.th-darmstadt.de/pub/preprints/IKDA-95-20.ps.g

Digital information and the 'privatisation of knowledge'

Purpose of this paper: To point out that past models of information ownership may not carry over to the age of digital information. The fact that public ownership of information (for example, by means of national and public library collections) created social benefits in the past does not mean that a greater degree of private sector involvement in information provision in the knowledge society of today is synonymous with an abandonment of past ideals of social information provision. Design/methodology/approach: A brief review of recent issues in digital preservation and national electronic heritage management, with an examination of the public/private sector characteristics of each issue. Findings: Private companies and philanthropic endeavours focussing on the business of digital information provision have done some things - which in the past we have associated with the public domain - remarkably well. It is probably fair to say that this has occurred against the pattern of expectation of the library profession. Research limitations/Implications:The premise of this paper is that LIS research aimed at predicting future patterns of problem solving in information work should avoid the narrow use of patterns of public-private relationships inherited from a previous, print-based information order. Practical implications: This paper suggests practical ways in which the library and information profession can improve digital library services by looking to form creative partnerships with private sector problem solvers. What is original/value of the paper? This paper argues that the LIS profession should not take a doctrinaire approach to commercial company involvement in 'our' information world. Librarians should facilitate collaboration between all parties, both public and private, to create original solutions to contemporary information provision problems. In this way we can help create pragmatic, non-doctrinaire solutions that really do work for the citizens of our contemporary information society

Object knowledge modulates colour appearance

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis

Cascading Bandits for Large-Scale Recommendation Problems

Abstract Most recommender systems recommend a list of items. The user examines the list, from the first item to the last, and often chooses the first attractive item and does not examine the rest. This type of user behavior can be modeled by the cascade model. In this work, we study cascading bandits, an online learning variant of the cascade model where the goal is to recommend K most attractive items from a large set of L candidate items. We propose two algorithms for solving this problem, which are based on the idea of linear generalization. The key idea in our solutions is that we learn a predictor of the attraction probabilities of items from their features, as opposing to learning the attraction probability of each item independently as in the existing work. This results in practical learning algorithms whose regret does not depend on the number of items L. We bound the regret of one algorithm and comprehensively evaluate the other on a range of recommendation problems. The algorithm performs well and outperforms all baselines

o.OM: Structured-Functional Communication between Computer Music Systems using OSC and Odot

International audienceO.—odot—is a portable media programming framework based on the OSC data encoding. It embeds a small expression language which allows writing and executing programs in OSC structures. The integration of programming and declarative functional descriptions within data transfer protocols enables structured and expressive communication in media systems: program snippets can be distributed in OSC messages, which evaluate to further OSC messages in the different communicating software. We present experiments using this framework in the OpenMusic computer-aided composition environment , and illustrate via case studies some advantages of such integrated system

Extreme Makeover: Bending the Rules to Reduce Risk Rewriting Complex Systems

Abstract. We describe our experience using XP to reimplement sophisticated, high-performance imaging software in a research environment. We focus espe-cially on practices we used to derive value from the existing software, notably reimplementation by ransacking and conversion as learning. Our experience suggests that some of the classic 12 practices which define XP should be ad-justed when there is a existing, well-structured system to serve as a guide.

Whisker spot patterns: a noninvasive method of individual identification of Australian sea lions (Neophoca cinerea)

Reliable methods for identification of individual animals are advantageous for ecological studies of population demographics and movement patterns. Photographic identification, based on distinguishable patterns, unique shapes, or scars, is an effective technique already used for many species. We tested whether photographs of whisker spot patterns could be used to discriminate among individual Australian sea lion (Neophoca cinerea). Based on images of 53 sea lions, we simulated 5,000 patterns before calculating the probability of duplication in a study population. A total of 99% (± 1.5 SD) of patterns were considered reliable for a population of 50, 98% (± 1.7 SD) for 100, 92% (± 4.7 SD) for 500, and 88% (± 5.7 SD) for 1,000. We tested a semiautomatic approach by matching 16 known individuals at 3 different angles (70°, 90°, and 110°), 2 distances (1 and 2 m), and 6 separate times over a 1-year period. A point-pattern matching algorithm for pairwise comparisons produced 90% correct matches of photographs taken on the same day at 90°. Images of individuals at 1 and 2 m resulted in 89% correct matches, those photographed at different angles and different times (at 90°) resulted in 48% and 73% correct matches, respectively. Our results show that the Chamfer distance transform can effectively be used for individual identification, but only if there is very little variation in photograph angle. This point-pattern recognition application may also work for other otariid species