A classification tree approach for the modeling of competing risks in discrete time

Advances in Data Analysis and Classification - Cause-specific hazard models are a popular tool for the analysis of competing risks data. The classical modeling approach in discrete time consists of...     

The measurement of frequency separations in high-resolution nuclear magnetic resonance spectra using a double-lock spectrometer

The rotation-ring-puckering problem of four-membered ring cyclobutane-type molecules with D _4h -D _2d conformations is formulated as a dynamical system in the eulerian angles and the polar coordinate ?. Classical and quantum-mechanical hamiltonians and their symmetry group O ⁺⁺(3) × D _∞h are discussed. The kinetic energy matrix coefficients g_mm are found to be irrational functions of the trigonometric polynomial 3 + cos 2? in the internal coordinate ?. It is shown that the energy matrix coefficients may all be expressed as Laurent coefficients by means of the hypergeometric function ₂ F ₁, the convergence being determined by the roots of the kinetic determinant. Selection rules and matrix elements for rotation-ring-puckering Raman transitions are given.     

Über ein neues Tribromphenol,das 1-Oxy-3, 4, 5-Tribrombenzol,und ein neues Tribrom-o-Kresol,das 1-Methyl-2-Oxy-4, 5, 6-Tribrombenzol

Ohne ZusammenfassungXV. Mitteilung: M. Kohn und A. Rosenfeld, Ein Beitrag zur Kenntnis der Pseudophenole. Monatshefte f. Chemie, 1925.     

The Development of Comprehension of Chance Language: Evaluation and Interpretation

Comprehension of chance language, such as is found in newspapers, is a fundamental aspect of statistical literacy. In this study, students' understandings of chance language were explored through responses to two items in surveys administered to 2,726 students from grades 5 to 11. One item involved evaluating the chance expressed in phrases from newspaper headlines using a number line, and responses were described in four levels of chance language evaluation. The other item involved interpreting, in context, an expression of percent chance, and responses were described in four levels of chance language interpretation. Students in higher grades were more likely to demonstrate higher levels of both evaluation and interpretation. The association between levels of evaluation and interpretation was further explored generally and in relation to one of the headlines involving percent. Implications for mathematics educators in relation to chance language in the curriculum across the years of schooling are discussed.     

Das Verhalten des Trinitroanisols zu tertiären Basen

Ohne Zusammenfassung     

Zur Kenntnis des chinoiden Oxydations-produktes des Methylendi-β-naphtols

Ohne Zusammenfassung     

Variational theory of Riemannian subspaces

If a subspace of a Riemannian manifold is varied the tensors associated with the subspace also vary. The appropriate concept of tensorial variation is introduced and the tensorial variations of several tensors are calculated. A general formula for the variation of an integral is given. Applications are made to the mean curvature integrals of hypersurfaces.