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61.
Every compact symmetric bilinear form B on a complex Hilbert space produces, via an antilinear representing operator, a real spectrum consisting of a sequence decreasing to zero. We show that the most natural analog of Courant's minimax principle for B detects only the evenly indexed eigenvalues in this spectrum. We explain this phenomenon, analyze the extremal objects, and apply this general framework to the Friedrichs operator of a planar domain and to Toeplitz operators and their compressions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
62.
Oscar García Josep Vehí Jose Campos e Matos António Abel Henriques Joan Ramon Casas 《Journal of Computational and Applied Mathematics》2008
An efficient health monitoring system for damage detection in civil engineering structures using on-line monitoring data is being developed to identify any possible damage in short time. The present work is based on the treatment of uncertainties, which is one of the basic common difficulties faced when modelling structures. A methodology, based on interval analysis (IA) theory [R.E. Moore, Interval Analysis, Prentice-Hall, Englewood Cliffs, NJ, 1966] applied to a numerical constraint satisfaction problem (CSP) [J.R. Casas, J.C. Matos, J.A. Figueiras, J. Vehí, O. García, P. Herrero, Bridge monitoring and assessment under uncertainty via interval analysis, in: Ninth International Conference On Structural Safety And Reliability—ICOSSAR2005, 2005. pp. 487–494], is implemented in the damage detection [J.R. Casas, J.C. Matos, J.A. Figueiras, J. Vehí, O. García, P. Herrero, Bridge monitoring and assessment under uncertainty via interval analysis, in: Ninth International Conference On Structural Safety And Reliability—ICOSSAR2005, 2005. pp. 487–494] and modelling system of a long-term monitoring project in order to achieve such an objective. An algorithm is being developed for using such methodology with the obtained data. 相似文献
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A highly enantioselective organocatalytic fluoromalonate addition to α,β-unsaturated aldehydes is reported. The reaction is catalyzed by simple and commercially available secondary amines, affording the corresponding 1,4-adducts with high yields and enantioselectivities. 相似文献
67.
Anna Fàbregas-Fernández Encarna García-Montoya Pilar Pérez-Lozano Josep M. Suñé-Negre Josep Ramon Ticó Montserrat Miñarro 《Accreditation and quality assurance》2010,15(5):297-304
There is currently no universal or standardized quality system for the recognition of excellence of a research center. Knowledge
and competence may not be enough in the current rapidly changing world in which high productivity and continuous improvement
are essential. The purpose of this study was to assess the impacts of implementing the ISO9001:2000:2000 standard in an academic
research center dedicated to R+D+I (research, development and innovation) in the pharmaceutical industry. The article describes
the stages we followed to implement the ISO9001:2000 system, which was achieved by integrating it into the previous regulatory
system of GMP (Good Manufacturing Practices). As a result of implementing ISO9001:2000, the center has seen distinct improvements,
such as fewer errors in project documentation, improved assessment of customer satisfaction, and the effective implementation
of periodic plans, e.g., in calibration, preventive maintenance, and investments. Overall, ISO9001:2000 implementation has
been beneficial for the organization and could be applied to other research centers. 相似文献
68.
Ramon Carbó-Dorca 《Journal of mathematical chemistry》2010,47(1):331-344
Complete matrix sums and inward products are employed within vector spaces to define a generalized scalar product, searching
at the same time for coherent definitions with the related general order norms. The theoretical background developed in this
way permits to connect such mathematical constructs with quantum similarity and QSPR. 相似文献
69.
In this work, we present a stabilized formulation to solve the inductionless magnetohydrodynamic (MHD) problem using the finite element (FE) method. The MHD problem couples the Navier–Stokes equations and a Darcy-type system for the electric potential via Lorentz’s force in the momentum equation of the Navier–Stokes equations and the currents generated by the moving fluid in Ohm’s law. The key feature of the FE formulation resides in the design of the stabilization terms, which serve several purposes. First, the formulation is suitable for convection dominated flows. Second, there is no need to use interpolation spaces constrained to a compatibility condition in both sub-problems and therefore, equal-order interpolation spaces can be used for all the unknowns. Finally, this formulation leads to a coupled linear system; this monolithic approach is effective, since the coupling can be dealt by effective preconditioning and iterative solvers that allows to deal with high Hartmann numbers. 相似文献