Using interior point solvers for optimizing progressive lens models with spherical coordinates

Research Report UPC-DEIO DR 2019Designing progressive lenses is a complex problem that has beenpreviously solved by formulating an optimization model based on Cartesiancoordinates. In this work a new progressive lens model using spherical co-ordinates is presented, and interior point solvers are used to solve this newoptimization model. Although this results in a highly nonlinear, nonconvex,continuous optimization problem, the new spherical coordinates model exhibitsbetter convexity properties compared to previous ones based on Cartesian co-ordinates. The real-world instances considered gave rise to nonlinear optimiza-tion problems of about 900 variables and 15000 constraints. Each constraintcorresponds to a point of the grid used to define the lens surface. The numberof variables depends on the precision of a B-spline basis used for the repre-sentation of the surface, and the number of constraints depends on the shapeand quality of the design. We present results of progressive lenses obtainedusing the AMPL modeling language and the nonlinear interior point solversIPOPT, LOQO and KNITRO. Computational results are reported, as wellas some examples of real-world progressive lenses calculated using this newmodel. Progressive lenses obtained are competitive in terms of quality withthose resulting from previous models that are used in commercial glasses.Peer ReviewedPreprin

Desenvolupament sostenible i visió global de les biblioteques

Posicionament de les biblioteques; Transformació global; SostenibilitatPositioning of libraries; Global transformation; SustainabilityPosicionamiento de las bibliotecas; Transformación global; SostenibilidadEn aquesta ponència de cloenda, l'autora exposa el concepte de desenvolupament sostenible i biblioteques, explica els objectius de desenvolupament sostenible (ODS), i com les biblioteques poden ajudar al desenvolupament d'aquests. Conclou amb la necessitat que les biblioteques esdevinguin promotores del canvi, i els bibliotecaris eixos dels motors del canvi

Cuatro ejemplos de emprendimiento en bibliotecas

Más allá de los libros. El papel de las bibliotecas emprendedoras en la promoción del bienestar económico. Es el título del informe que el Carnegie UK Trust ha publicado sobre los proyectos que ha impulsado en Inglaterra y Gales, llevados a cabo entre julio de 2013 y marzo de 2014. Está firmado por Jennifer Peachey, la recién incorporada responsable de la política del Carnegie UK Trust que destaca los factores que han contribuido a su éxito, el debate que han logrado establecer entre las autoridades bibliotecarias del Reino Unido, Escocia, Gales e Irlanda del Norte y una serie de recomendaciones finales

A summary of IFLA, Eblida, Liber and Fesabid activities in 2014

This review reflects on the activities carried out during 2014 by four professional associations on Library and Information Science: IFLA (International Federation of Library Associations and Institutions), Eblida (European Bureau of Library, Information and Documentation Associations), Liber (Association of European Research Libraries) and Fesabid (Spanish Federation of Archive, Library, Documentation and Museum Societies). Regarding the situation in Spain, the author regrets the current fragmentation into small local associations, despite the existence of a federation (Fesabid), because this weakens the Spanish professional community as a whole

Libraries and the need to protect authors’ rights

The position of libraries as society’s guarantors of thefreedom of access to knowledge persists despite barriers to lending digital content, to the collection of digital content in order to preserve it from the “digital black hole” and to the development of digital collections in libraries. The evidence of the lack of minimum international legal standards in a digital environment and in our library sector has raised concerns over the global legal framework that is needed to facilitate the use of digital content in a way that is balanced for both libraries and copyright. The article includes a brief introduction about initiatives by library associations such as IFLA, working together with WIPO to boost TLIB, an international treaty on exceptions and limitations to copyright for libraries, and the EBLIDA campaign, ‘The Right to e-Read’

2.0 integral dentro y fuera de la Biblioteca Nacional de España

Desde la creación de su página en Facebook, la Biblioteca Nacional de España ha ido creando un entorno 2.0 caracterizado por la apertura de canales institucionales en diversas redes sociales, como YouTube o Flickr, amén de otras iniciativas como la publicación de un blog corporativo o la incorporación de funcionalidades 2.0 a la Biblioteca Digital Hispánica. A esto se añaden otras iniciativas en marcha, como la apertura de un canal en SlideShare o la inminente presencia en Twitte

Ideas map for the transformation of IFLA's strategy

This is the report of the International Federation of Libraries Associations and Institutions (IFLA) 2017-2019 President’s Program. It is the narrative of the presidential program based on the Ideas Map inspired by an exhaustive analysis of how IFLA is developing in accordance with its strategic plan 2016- 2021. The activities that IFLA has recently started are focused on this new approach, taking advantage of the opportunity of transformation that has been provided by the Bill & Melinda Gates Foundation, Global Libraries Legacy. I also discuss the needs that I have identified and I consider necessary to fulfil the expectations defined in my presidential theme: Libraries: motors of change