Birefringence analysis of segmented cladding fiber

We present a full-vectorial modal analysis of a segmented cladding fiber (SCF). The analysis is based on the H-field vectorial finite element method (VFEM) employing polar mesh geometry. Using this method, we have analyzed the circular SCF and the elliptical SCF. We have found that the birefringence of the circular SCF is very small (1.0×10−8). Birefringence of a highly elliptical SCF can be altered to some extent by the number of segments and duty cycle of segmentation in the segmented cladding. However, the change is not profound. The analysis shows that the circular SCF possesses low birefringence and that the segmented cladding does not add any significant birefringence in an elliptical fiber. This result strongly indicates that small deviations in the segmented cladding parameters arising from fabrication process do not significantly affect the birefringence of the fiber

Seed coat fragments, a major source of cotton yarn imperfections

A method to differentiate cultivars depending on their SCFcontents on yarn was developped in CIRAD CA using a GGP Uster Eveness Tester. Results indicate a high SCF heritability,but fabrication of yam is too costly to be used for breeding programs. 50, anew method, using image analysis, has been developped for counting andsizing up SCF on card web. SCF counts were made on card web and compared to those obtained by Uster Tester III on 20 texn 37 tex yarns for 30 cottons. Number of SCF on yarn can bi predicted wiht R² as great as 80%. (Résumé d'auteur

Neutral and Charged Anyon Fluids

(Review) Properties of neutral and charged anyon fluids are examined, with the main focus on the question whether or not a charged anyon fluid exhibits a superconductivity at zero and finite temperature. Quantum mechanics of anyon fluids is precisely described by Chern-Simons gauge theory. The random phase approximation (RPA), the linearized self-consistent field method (SCF), and the hydrodynamic approach employed in the early analysis of anyon fluids are all equivalent. Relations and differences between neutral and charged anyon fluids are discussed. It is necessary to go beyond RPA and the linearized SCF, and possively beyond the Hartree-Fock approximation, to correctly describe various phenomena such as the flux quantization, vortex formation, and phase transition. Topics includes: Anyons, Aharonov-Bohm effect, Chern-Simons gauge theory, Hartree-Fock ground state, RPA and SCF, Path integral representation, RPA = linearized SCF, Response functions, Phonons and plasmons, Hydrodynamic description, Effective theory, Meissner effect at zero and finite temperature, de Haas - van Alphen effect in SCF, Thermodynamic potential in inhomogeneous fields, T_c, Other important issues. (To appear in Int. J. Mod. Phys. B)Comment: 99 journal pages, plain Tex, 13 figures not included (please request), UMN-TH-1106/9

Using Qualitative Hypotheses to Identify Inaccurate Data

Identifying inaccurate data has long been regarded as a significant and difficult problem in AI. In this paper, we present a new method for identifying inaccurate data on the basis of qualitative correlations among related data. First, we introduce the definitions of related data and qualitative correlations among related data. Then we put forward a new concept called support coefficient function (SCF). SCF can be used to extract, represent, and calculate qualitative correlations among related data within a dataset. We propose an approach to determining dynamic shift intervals of inaccurate data, and an approach to calculating possibility of identifying inaccurate data, respectively. Both of the approaches are based on SCF. Finally we present an algorithm for identifying inaccurate data by using qualitative correlations among related data as confirmatory or disconfirmatory evidence. We have developed a practical system for interpreting infrared spectra by applying the method, and have fully tested the system against several hundred real spectra. The experimental results show that the method is significantly better than the conventional methods used in many similar systems.Comment: See http://www.jair.org/ for any accompanying file

Symmetry and equivalence restrictions in electronic structure calculations

A simple method for obtaining MCSCF orbitals and CI natural orbitals adapted to degenerate point groups, with full symmetry and equivalnece restrictions, is described. Among several advantages accruing from this method are the ability to perform atomic SCF calculations on states for which the SCF energy expression cannot be written in terms of Coulomb and exchange integrals over real orbitals, and the generation of symmetry-adapted atomic natural orbitals for use in a recently proposed method for basis set contraction

Parallel Self-Consistent-Field Calculations via Chebyshev-Filtered Subspace Acceleration

Solving the Kohn-Sham eigenvalue problem constitutes the most computationally expensive part in self-consistent density functional theory (DFT) calculations. In a previous paper, we have proposed a nonlinear Chebyshev-filtered subspace iteration method, which avoids computing explicit eigenvectors except at the first SCF iteration. The method may be viewed as an approach to solve the original nonlinear Kohn-Sham equation by a nonlinear subspace iteration technique, without emphasizing the intermediate linearized Kohn-Sham eigenvalue problem. It reaches self-consistency within a similar number of SCF iterations as eigensolver-based approaches. However, replacing the standard diagonalization at each SCF iteration by a Chebyshev subspace filtering step results in a significant speedup over methods based on standard diagonalization. Here, we discuss an approach for implementing this method in multi-processor, parallel environment. Numerical results are presented to show that the method enables to perform a class of highly challenging DFT calculations that were not feasible before

A Phase-Space Approach to Collisionless Stellar Systems Using a Particle Method

A particle method for reproducing the phase space of collisionless stellar systems is described. The key idea originates in Liouville's theorem which states that the distribution function (DF) at time t can be derived from tracing necessary orbits back to t=0. To make this procedure feasible, a self-consistent field (SCF) method for solving Poisson's equation is adopted to compute the orbits of arbitrary stars. As an example, for the violent relaxation of a uniform-density sphere, the phase-space evolution which the current method generates is compared to that obtained with a phase-space method for integrating the collisionless Boltzmann equation, on the assumption of spherical symmetry. Then, excellent agreement is found between the two methods if an optimal basis set for the SCF technique is chosen. Since this reproduction method requires only the functional form of initial DFs but needs no assumptions about symmetry of the system, the success in reproducing the phase-space evolution implies that there would be no need of directly solving the collisionless Boltzmann equation in order to access phase space even for systems without any special symmetries. The effects of basis sets used in SCF simulations on the reproduced phase space are also discussed.Comment: 16 pages w/4 embedded PS figures. Uses aaspp4.sty (AASLaTeX v4.0). To be published in ApJ, Oct. 1, 1997. This preprint is also available at http://www.sue.shiga-u.ac.jp/WWW/prof/hozumi/papers.htm