1,108 research outputs found

    FESA 3.0 : Overcoming the XML/RDBMS Impedance Mismatch

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    The Front End System Architecture (FESA) framework developed at CERN takes an XML-centric approach to modelling accelerator equipment software. Among other techniques, XML Schema is used for abstract model validation, while XSLT drives the generation of code. At the same time all the information generated and used by the FESA framework is just a relatively small subset of a much wider realm of Controls Configuration data stored in a dedicated database and represented as a sophisticated relational model. Some data transformations occur in the XML universe, while others are handled by the database, depending on which technology is a better fit for the task at hand. This paper describes our approach to dealing with what we call the “XML/Relational impedance mismatch” – by analogy to Object/Relational impedance mismatch – that is how to best leverage the power of an RDBMS as a back-end for an XML-driven framework. We discuss which techniques work best for us, what to avoid, where the potential pitfalls lie. All this is based on several years of experience with a living system used to control the world’s biggest accelerator complex

    JDATAVIEWER – JAVA-Based Charting Library

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    The JDataViewer is a Java-based charting library developed at CERN, with powerful, extensible and easy to use function editing capabilities. Function edition is heavily used in Control System applications, but poorly supported in products available on the market. The JDataViewer enables adding, removing and modifying function points graphically (using a mouse) or by editing a table of values. Custom edition strategies are supported: developer can specify an algorithm that reacts to the modification of a given point in the function by automatically adapting all other points. The library provides all typical 2D plotting types (scatter, polyline, area, bar, HiLo, contour), as well as data point annotations and data indicators. It also supports common interactors to zoom and move the visible view, or to select and highlight function segments. A clear API is provided to configure and customize all chart elements (colors, fonts, data ranges ...) programmatically, and to integrate non-standard rendering types, interactors or chart decorations (custom drawings). Last but not least, the library offers class-leading performance

    The new computer program for three dimensional relativistic hydrodynamical model

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    An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.Comment: Quark Matter 2005 Poster Session Proceedin

    Accelerator Data Foundation : How it all fits together

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    Since 2003, a coherent data management approach was envisaged for the needs of installing, commissioning, operating and maintaining the LHC. Data repositories in the distinct domains of physical equipment, installed components, controls configuration and operational data have been established to cater for these different aspects. The interdependencies between the domains have been implemented as a distributed database. This approach, based on a very wide data foundation, has been used for the LHC and is being extended to the CERN accelerator complex

    Variaciones espaciales y temporales del registro del límite K/T en Haiti: implicaciones acerca del evento o eventos

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    El registro en la capa del límite K/T (KTB), en diferentes localidades de la Península Meridional de Haití, muestra claras evidencias de disrupciones físicas causadas por el impacto postulado de un bólico al final del Maastrichtiense. Tanto el registro bioestratigráfico como el litológico de la capa KTB, en diferentes localidades, muestra también diversos grados de mezcla, con componentes faunísticos de edades congruentes con los bioeventos característicos de la transición del límite, equivalentes a la parte terminal de la Zona de Abathomphalus mayaroensis y partes de las Zonas de Guembelitria cretacea y de Parvularugoglobigerina eugubina. La nanoflora calcárea también muestra taxones de la transición, concurrentes con los datos de foraminíferos, e indicativos de las Subzonas de Micula murus y Micula prinsii, así como de la Subzona de Cruciplacolithus primus (CP1a), del Paleoceno basal. La capa del límite tiene variaciones en su potencia, con un máximo de 75cm en el estratotipo de la Formación Beloc, y a techo de la capa principal tectítica hay un máximo de iridio. Los análisis geoquímicos y la datación radiométrica han demostrado también que las esférulas son tectitas (Premo e Izett, 1991) que pueden estar relacionadas cronológicamente con el evento de impacto registrado en Chicxulub, Yucatán, México, hace 65 Ma. Aún más, las delicadas estructuras sedimentarias primarias en la capa del límite son constantes en todos los afloramientos, aunque hay diferencias espaciales incluso a corta distancia. Además, en las áreas adyacentes al estratotipo (Platon Piton y Madame Toussaint) se encuentra una capa volcanogénica, bajo el nivel tectítico principal relacionado con el evento de Chicxulub, que muestra una laminación cruzada, tanto conspicua como críptica, indicativa de procesos de flujo complejos, multifásicos y subacuáticos que afectaron a la sedimentación de forma parecida a la del lecho KTB. Se conocen tales estructuras como características de la acción de ondas oscilantes sobre la cohesión de los sedimentos. El movimiento de las aguas asociado con un seiche es el único análogo actual conocido de un flujo subacuático que proporcione un mecanismo plausible para explicar el que varios niveles de la columna de agua, en una gran cuenca, pueden oscilar para desarrollar las estructuras observadas. Dada la magnitud del impacto del bólido, debieron desarrollarse ‘megaseiches’ en los océanos a escala mundial y, subsecuéntemente, se producirían otros ‘megaseiches’ más localizados durante los reajustes principales de la corteza. Esos fenómenos pueden así explicar la heterogeneidad de pautas y discrepancias faunísticas observadas en varias localidades del KTB, de distinta profundidad de depósito, en el mundo. Las estructuras representan un registro de los movimientos del agua y de la resuspensión de los sedimentos en momentos diferentes. Tal como se ha observado en seiches modernos a pequeña escala, la duración y atenuación de los movimientos del agua y la magnitud de la tracción y resuspensión estuvieron controlados por diversos modos oscilatorios que dieron lugar a complejas estructuras sedimentarias y al retrabajamiento de los microfósiles

    CERN Proton Synchrotron Complex High-Level Controls Renovation

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    After a detailed study of the Proton Synchrotron (PS) complex requirements by experts of CERN controls & operation groups, a proposal to develop a new system, called Injector Controls Architecture (InCA), was presented to and accepted by the management late 2007. Aiming at the homogenisation of the control systems across CERN accelerators, InCA is based on components developed for the Large Hadron Collider (LHC) but also new components required to fulfil operation needs. In 2008, the project was in its elaboration phase and we successfully validated its architecture and critical use-cases during several machine development sessions. After description of the architecture put in place and the components used, this paper describes the planning approach taken combining iterative development phases with deployment in operation for validation sessions

    The STAR Silicon Strip Detector (SSD)

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    The STAR Silicon Strip Detector (SSD) completes the three layers of the Silicon Vertex Tracker (SVT) to make an inner tracking system located inside the Time Projection Chamber (TPC). This additional fourth layer provides two dimensional hit position and energy loss measurements for charged particles, improving the extrapolation of TPC tracks through SVT hits. To match the high multiplicity of central Au+Au collisions at RHIC the double sided silicon strip technology was chosen which makes the SSD a half million channels detector. Dedicated electronics have been designed for both readout and control. Also a novel technique of bonding, the Tape Automated Bonding (TAB), was used to fullfill the large number of bounds to be done. All aspects of the SSD are shortly described here and test performances of produced detection modules as well as simulated results on hit reconstruction are given.Comment: 11 pages, 8 figures, 1 tabl

    Antideuteron and deuteron production in mid-central Pb+Pb collisions at 158AA GeV

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    Production of deuterons and antideuterons was studied by the NA49 experiment in the 23.5% most central Pb+Pb collisions at the top SPS energy of sNN\sqrt{s_{NN}}=17.3 GeV. Invariant yields for dˉ\bar{d} and dd were measured as a function of centrality in the center-of-mass rapidity range 1.2<y<0.6-1.2<y<-0.6. Results for dˉ(d)\bar{d}(d) together with previously published pˉ(p)\bar{p}(p) measurements are discussed in the context of the coalescence model. The coalescence parameters B2B_2 were deduced as a function of transverse momentum ptp_t and collision centrality.Comment: 9 figure
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