Field quality in the twin aperture D2 dipoles for LHC under asymmetric excitation

Twin aperture D2 magnets are one of the several types of dipoles to be built by BNL for the interaction regions of LHC. To minimize the number of dipole correctors required in the interaction regions, D2 will also be used as part of the steering system. Consequently, the operating fields in the two apertures may differ by up to ~10at 7 TeV operation and ~33at injection in order to compensate for the strengths of the correctors that would otherwise be required. Such asymmetric excitation of the two apertures may induce undesirable field harmonics. The saturation behavior of various harmonics is studied using POISSON and OPERA-2D. It is shown that the changes in harmonics resulting from the anticipated asymmetry are within tolerable limits. (2 refs)

Genetic Algorithms Applied to Inconsistent Matrices Correction in the Analytic Hierarchy Process (AHP)

Making Decision in non-structured problems is not a simple task. For this reason, decision makers use Decision Support Systems (DSS). These kinds of systems implement techniques and algorithms in order to improve the decision process. Analytic Hierarchy Process (AHP) is one of these techniques which yields a ranking scale of alternatives based on criteria and alternative matrices. These matrices make a pairwise comparison between a set of elements compared and must be complete and consistent in order to be processed with AHP. Incompleteness and inconsistency emerge as a consequence of the large data required to be compared by an expert, which exceeds his or her human abilities. Genetic Algorithms (GA) is a powerful used technique which provides simplicity, broad applicability and flexibility for search problems. In this work a GA model is exposed, being its aims to help the expert to fill the matrix and provide reasonable judgments by suggesting possible values.Sociedad Argentina de Informática e Investigación Operativ

Genetic Algorithms Applied to Inconsistent Matrices Correction in the Analytic Hierarchy Process (AHP)

Making Decision in non-structured problems is not a simple task. For this reason, decision makers use Decision Support Systems (DSS). These kinds of systems implement techniques and algorithms in order to improve the decision process. Analytic Hierarchy Process (AHP) is one of these techniques which yields a ranking scale of alternatives based on criteria and alternative matrices. These matrices make a pairwise comparison between a set of elements compared and must be complete and consistent in order to be processed with AHP. Incompleteness and inconsistency emerge as a consequence of the large data required to be compared by an expert, which exceeds his or her human abilities. Genetic Algorithms (GA) is a powerful used technique which provides simplicity, broad applicability and flexibility for search problems. In this work a GA model is exposed, being its aims to help the expert to fill the matrix and provide reasonable judgments by suggesting possible values.Sociedad Argentina de Informática e Investigación Operativ

A Cross-Over in the Enstrophy Decay in Two-Dimensional Turbulence in a Finite Box

The numerical simulation of two-dimensional decaying turbulence in a large but finite box presented in this paper uncovered two physically different regimes of enstrophy decay. During the initial stage, the enstrophy, generated by a random Gaussian initial condition, decays as t^{-gamma} with gamma approximately 0.7-0.8. After that, the flow undergoes a transition to a gas or fluid composed of distinct vortices. Simultaneously, the magnitude of the decay exponent crosses over to gamma approximately 0.4. An exact relation for the total number of vortices, N(t), in terms of the mean circulation of an individual vortex is derived. A theory predicting that N(t) is proportional to t^{-xi} and the magnitudes of exponents gamma=2/5 and xi=4/5 is presented and the possibility of an additional very late-time cross-over to gamma=1/3 and xi=2/3 is also discussed.Comment: 11 pages, 7 figure

Aplicación de algoritmos genéticos a la corrección de matrices inconsistentes en el Proceso Analítico Jerárquico (AHP)

La combinación de diversas técnicas de la inteligencia artificial da lugar a que problemas complejos puedan ser resueltos de formas más eficientes y eficaces desde el punto de vista práctico. Puede aprovecharse así la utilización de técnicas muy estudiadas y potentes, como los algoritmos genéticos, a la solución de los problemas de consistencia de las matrices que se utilizan en el Proceso Analítico Jerárquico, para reducir su inconsistencia al mismo tiempo que se evita introducir una arbitrariedad ajena a la decisión de un experto en dichas matrices. La inconsistencia surge producto de la complejidad inherente a la toma de decisiones en donde los factores a considerar cumplen con dos criterios: el criterio objetivo, que determina múltiples y complejas relaciones entre las variables a tener en cuenta; y el criterio subjetivo, vinculado con los conocimientos, capacidades y percepciones de la persona encargada de tomar la decisión.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Cored Rutherford cables for the GSI fast ramping synchrotron

The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 200 T/spl middot/m and 100 T/spl middot/m. Fast ramp times are needed, which can cause significant problems for the magnets, particularly in the areas of ac loss and field distortion. This paper discusses the 200 T/spl middot/m ring, which will use Cos/spl theta/ magnets based on the RHIC dipole design. We discuss the reasons for choosing Rutherford cable with a resistive core and report loss measurements carried out on cable samples. These measurements are compared with theoretical calculations using measured values of inter-strand resistance. Reasonably good agreement is found, but there are indications of nonuniformity in the adjacent resistance R/sub a/. Using these measured parameters, losses and temperature rise are calculated for a RHIC dipole in the operating cycle of the accelerator. A novel insulation scheme designed to promote efficient cooling is described

Genetic Algorithms Applied to Inconsistent Matrices Correction in the Analytic Hierarchy Process (AHP)

Making Decision in non-structured problems is not a simple task. For this reason, decision makers use Decision Support Systems (DSS). These kinds of systems implement techniques and algorithms in order to improve the decision process. Analytic Hierarchy Process (AHP) is one of these techniques which yields a ranking scale of alternatives based on criteria and alternative matrices. These matrices make a pairwise comparison between a set of elements compared and must be complete and consistent in order to be processed with AHP. Incompleteness and inconsistency emerge as a consequence of the large data required to be compared by an expert, which exceeds his or her human abilities. Genetic Algorithms (GA) is a powerful used technique which provides simplicity, broad applicability and flexibility for search problems. In this work a GA model is exposed, being its aims to help the expert to fill the matrix and provide reasonable judgments by suggesting possible values.Sociedad Argentina de Informática e Investigación Operativ