Non-identical particle correlation analysis as a probe of transverse flow

Non-identical two particle correlation functions probe asymmetries between the average space-time emission points of different particle species. The system collective expansion would produce such asymmetry because massive particles, such as protons, are on average more pushed towards the edge of the system, than lighter ones, i.e. pions. Measuring pion-kaon, pion-proton and kaon-proton correlation functions, using the STAR detector, we show that the data are consistent with the effect of transverse flow in Au-Au collisions at $\sqrt{s_{NN}} = 130$ GeV.Comment: 4 pages, 2 figures, 1 table, Contribution to Quark Matter 2002, Nantes, France, July 200

Des destinées judiciaires pénalement et socialement marquées

International audienceLes statistiques policières et judiciaires dévoilent régulièrement une focalisation de l’appareil répressif sur certains publics, notamment les franges les plus marginalisées de la société. Certains auteurs déduisent de telles données la preuve d’une sévérité accrue des organes de jugement à l’encontre des classes sociales défavorisées et des minorités, sinon de véritables pratiques judiciaires discriminatoires. Ce chapitre se présente comme une contribution à ce chantier de recherche. L’objectif n’est pas de nous intéresser aux mécanismes sélectifs de production de la clientèle pénale, mais plutôt de comprendre ce qui se joue une fois les magistrats saisis d’une affaire. Au bout du compte, quel concours ces derniers apportent-ils à la reproduction des clivages sociaux ? Faut-il voir dans la surreprésentation des populations les plus vulnérables parmi les condamnés, la preuve d’une sévérité accrue des instances de jugement, susceptible d’être rapportée à des pratiques judiciaires discriminatoires

Observable implications of geometrical and dynamical aspects of freeze-out in heavy ion collisions

Using an analytical parameterization of hadronic freeze-out in relativistic heavy ion collisions, we present a detailed study of the connections between features of the freeze-out configuration and physical observables. We focus especially on anisotropic freeze-out configurations (expected in general for collisions at finite impact parameter), azimuthally-sensitive HBT interferometry, and final-state interactions between non-identical particles. Model calculations are compared with data taken in the first year of running at RHIC; while not perfect, good agreement is found, raising the hope that a consistent understanding of the full freeze-out scenario at RHIC is possible, an important first step towards understanding the physics of the system prior to freeze-out.Comment: 36 pages, 56 figures, 2 tables; version accepted for publication in PRC: some figures, references and discussion added; now also discusses classical versus quantum statistic

A “promessa da diferença” dos supermercados cooperativos: tornar acessíveis os produtos de qualidade através de cadeias alimentares sustentáveis e democráticas?

In recent years, collaborative and participatory supermarkets are spreading all over Europe, especially in France, as a new purchase model. This article aims to analyse the “promise of difference” (LE VELLY, 2017) that distinguishes this model from the current food offer. This promise is assessed both through the analysis of those projects in terms of products selection, work organisation and decision making, and through the implementation of concrete regulation activities. The methodological tools we used were content analysis of speeches, documents and on-line newpapers communication, as well as participant observation. The main results show that these models emerge as an alternative to the current food offer, both conventional supermarkets and alternative food networks. The study contributes to demonstrate that these cooperative supermarkets are shaped taking into account economic (reasonable price of products, reduction of fixed costs), social (accessibility, creation of a space to exchange and share, participation to the decision making) and environmental (local and organic products) issues. They inspire on conventional devices in terms of accessibility (low prices, long opening hours) and variety of products range. However, they distinguish themselves, in the first place, for being non-profit organisations, reinvesting the profits into the cooperative itself or into solidarity projects, but also by actively involving consumers in decision-making.En los últimos años, los supermercados colaborativos y participativos se están extendiendo por toda Europa, especialmente en Francia, como un nuevo modelo de compra. Este artículo pretende analizar la “promesa de diferencia" (LE VELLY, 2017) que distingue este modelo de la oferta actual de alimentos. Esta promesa se evalúa a través del análisis de esos proyectos en términos de selección de productos, organización del trabajo y toma de decisiones, y mediante la implementación de actividades de regulación concretas. La metodología se basa en el análisis de contenido de discursos, documentos y comunicaciones en los periódicos en linea, así como en la observación participante. Los principales resultados muestran que estos modelos surgen como alternativas, tanto a los supermercados convencionales como a las redes alimentarias alternativas. El estudio contribuye a demostrar que estas cooperativas se configuran teniendo en cuenta los aspectos económicos (precio razonable de los productos, reducción de los costos fijos), sociales (accesibilidad, creación de espacio para intercambiar y compartir, participación en la toma de decisiones) y ambientales (productos locales y/o biológicos). Se inspiran en los supermercados convencionales en términos de accesibilidad (precios bajos, horarios de apertura prolongados) y variedad de productos. Sin embargo, se distinguen por ser organizaciones sin fines de lucro, reinvirtiendo los lucros en la misma cooperativa o en proyectos solidarios, e por involucrar activamente a los consumidores en la toma de decisiones.Nos últimos anos, os supermercados cooperativos e participativos estão se espalhando por toda Europa, especialmente na França, como um novo modelo de compra. Este artigo tem como objetivo analisar a “promessa de diferença" (LE VELLY, 2017) que distingue esse modelo da atual oferta de alimentos. Esta promessa é avaliada tanto através da análise desses projetos em termos de seleção de produtos, organização do trabalho e tomada de decisões, como através da implementação de atividades de regulação concretas. A metodologia baseia-se na análise de conteúdo de discursos, documentos e comunicação em jornais on-line, assim como em observação participante. Os principais resultados mostram que esses modelos emergem como uma alternativa, tanto aos supermercados convencionais quanto às redes alternativas. O estudo contribui para demonstrar que essas cooperativas se estruturam levando em conta os aspectos: econômicos (preço razoável dos produtos, redução dos custos fixos), sociais (acessibilidade, criação de espaços de troca e compartilhamento, participação na tomada de decisões) e ambientais (produtos locais e/ou orgânicos). Inspiram-se nos modelos dos supermercados convencionais em termos de acessibilidade (preços baixos, horários de funcionamento prolongados) e variedade de produtos. Porém, distinguem-se primeiramente por serem organizações sem fins lucrativos, reinvestindo o lucro na própria cooperativa ou em projetos solidários, além de envolverem ativamente os consumidores na tomada de decisões

Comparison between system design optimization strategies for more electric aircraft network.

The aircraft electric network is a complex system, consisting of many different elements integrated to form a unique entity, designed to perform a well-defined mission. In the current state, the network conceptual design is based on standards defined by the aircraft manufacturer. As a consequence, electric subsystem suppliers are doing local optimizations to fulfill these standards in a separated way through a “mechanistic approach”. This results in a set of optimized subsystems which is not necessarily “optimal” with respect to the network level. To overcome this problem, we present a design approach called EPFM (Extended Pareto Front Method) based on separated subsystem optimizations which aims at finding an optimal configuration of the electrical network at the system level. The EPFM is discussed with regard to the computational cost and the collaboration requirements in the aeronautical industrial context and compared with the classical mechanistic approach

Comparison between system design optimization strategies for more electric aircraft networks

Nowadays, embedded aircraft system contains electrical devices which must cooperate in safe and light weight network. For designing such systems, different local strategies have been developed but no global optimization has been performed so far. In this paper, we present and compare three strategies applied to the sizing of a whole network of more electric aircraft: a simplified case study with only two components is considered to illustrate methodological issues. The quality of the solution found from each method is compared, with regards to the “cost of the collaborative approach” and the volume of data generation. This comparison should provide system designers an evaluation of the applicability of these methods according to the nature of the design problem

A multilevel double loop approach for the design of onboard flight networks

After testing different existing design methods for complex problems, we have concluded that a good approach based on system decomposition must coordinate the design process of components to reach the system optimum. In this paper, we present a multilevel collaborative approach for designing complex systems based on several loops (here 2). A system level optimization loop added to lead optimizations of components at their optimal solutions. This method was applied to the sizing of a simplified embedded electric network with single source–load configuration