Bin Packing and Related Problems: General Arc-flow Formulation with Graph Compression

We present an exact method, based on an arc-flow formulation with side constraints, for solving bin packing and cutting stock problems --- including multi-constraint variants --- by simply representing all the patterns in a very compact graph. Our method includes a graph compression algorithm that usually reduces the size of the underlying graph substantially without weakening the model. As opposed to our method, which provides strong models, conventional models are usually highly symmetric and provide very weak lower bounds. Our formulation is equivalent to Gilmore and Gomory's, thus providing a very strong linear relaxation. However, instead of using column-generation in an iterative process, the method constructs a graph, where paths from the source to the target node represent every valid packing pattern. The same method, without any problem-specific parameterization, was used to solve a large variety of instances from several different cutting and packing problems. In this paper, we deal with vector packing, graph coloring, bin packing, cutting stock, cardinality constrained bin packing, cutting stock with cutting knife limitation, cutting stock with binary patterns, bin packing with conflicts, and cutting stock with binary patterns and forbidden pairs. We report computational results obtained with many benchmark test data sets, all of them showing a large advantage of this formulation with respect to the traditional ones

Relatório de estágio na Câmara Municipal da Ribeira Grande

Este trabalho surge como resultado do estágio desenvolvido na Câmara Municipal da Ribeira Grande, ilha de S. Miguel, o qual pretendeu fazer a ponte entre a prática realizada em contexto académico e a prática profissional. Ilustra assim, as diferentes propostas de requalificação do espaço urbano, os pareceres e opiniões dadas a alguns projetos já existentes e as soluções encontradas para situações e problemas que foram surgindo, ao longo do meu período de permanência na referida Câmara; ABSTRACT: Internship Report on Ribeira Grande City Council In this report I will present all the work that I have done during my internship on Ribeira Grande city council in S. Miguel Island. Here I will present the conection with the academical skills and the professional practice. This report will also include the proposals of different requalifications for the urban space and the given opinions for some other existent projects. I am also going to enumerate the solutions for some difficulties found during my internship in the city council

Formación con sentido. Narrativas de vida en la construcción de profesionalidad de educadores de música

A partir de tres relatos de vida interpretados por educadores musicales, este artículo desea contribuir al universo de la formación inicial y continua de los docentes. Un espacio sensible, delicado, continuamente probando y justifica, por tanto, una contribución de los conocimientos "no oficiales". Y la didáctica de la música significativa es entender los caminos de vida reconocidos positivamente en éstos educadores en sus comunidades. ¿Qué podría estar detrás de un educador que lleva a la creatividad, la irreverencia, el entusiasmo entre sus alumnos? Qué “sontido” tuvo su formación inicial y/o contínua?Starting from three life stories performed by music educators, this article seeks to contribute to the universe of initial and continuous training of teachers. A sensitive, delicate, continually testing and justifies, therefore, a contribution to the "unofficial" knowledge. And music didactics is significant to understand the paths of life positively recognized in these educators on their communities. What could be behind an educator that leads to creativity, irreverence and enthusiasm among their students? What "sound meaning" had his initial and continuous training

Separating expansion from contraction: generalized TOV condition, LTB models with pressure and Λ\LambdaCDM

We discuss the existence of a dividing shell separating expanding and collapsing regions in spherically symmetric solutions with pressure. We obtain gauge invariant conditions relating not only the intrinsic spatial curvature of the shells to the ADM mass, but also a function of the pressure which we introduce that generalises the Tolman-Oppenheimer-Volkoff equilibrium condition, in the framework of a 3+1 spacetime splitting. We consider the particular case of a Lema\^itre-Tolman-Bondi dust models with a cosmological constant (a $\Lambda$-CDM model) as an example of our results.Comment: Proceedings of 'Invisible Universe International Conference', Paris, June 29- July 3, 2009 ; 5pp, 4 fig

Evaluating Evangelisation in Faith-Based Organisations: A Study of Catholic Educational Centres

Whilst many studies have shown the positive impact which faith-based organisations have contributed to global development, a question arises over the effectiveness of these institutions at imparting to their beneficiaries what makes them unique – their faiths. This study seeks to review the literature and interview key members of Catholic faith-based organisations to better understand the role that evangelisation, which is defined as “bringing the Good News of Jesus into every human situation,” plays in their work. The study focuses in particular on Catholic educational organisations and seeks to understand if they have institutionalised measures of success for this component of their ministry. The research finds that there is a great shortage of academic study on this element of the faith-based nonprofit sector. Furthermore, it was found that although faith-based organisations are by their nature defined by their religious aspect, this element is not universally measured, nor seen as necessarily the primary focus of organisations’ work. Through brief questionnaires, it was determined that evaluation methods differ amongst Catholic organisations in different geographical regions. Additionally, at times it may simply be impractical or irrelevant to measure the outcome of this evangelisation component of an organisation’s work. Notwithstanding this, the questionnaires found that measures of some elements of spiritual development are being used either formally or informally in many Catholic educational centres around the world

A criatura que sobrevive ao criador

A contracapa de O Ano da Morte de Ricardo Reis apresenta duas frases curiosas, uma de Fernando Pessoa, “Ricardo Reis nasceu em 1887 (não me lembro do dia e do mês, mas tenho-os algures), no Porto, é médico e está presentemente no Brasil”, e outra de Saramago, “Ricardo Reis regressou a Portugal depois da morte de Fernando Pessoa”, que apresentam a personagem à volta da qual gira a ação. A primeira define quem ele é, a segunda insere-o a história, dandonos uma informação temporal introdutória