Are Drivers\u27 Manuals Understandable?

In 1984, researchers determined that the readability of state drivers\u27 manuals exceeded the average literacy levels in the United States. Because text complexity threatened the ability of license applicants and practicing drivers to understand the information presented in the manuals, a potential safety risk was indicated. This study analyzes recent editions of the manuals using readability formulas and formal text presentation ratings. It was found that the average difficulty of the drivers\u27 manuals was reduced by more than one grade level and that the 1994 manuals are clearly superior to their earlier versions, but that, in the interest of highway safety, improvements should still be sought

A Projective C*-Algebra Related to K-Theory

The C*-algebra qC is the smallest of the C*-algebras qA introduced by Cuntz in the context of KK-theory. An important property of qC is the natural isomorphism of K0 of D with classes of homomorphism from qC to matrix algebras over D. Our main result concerns the exponential (boundary) map from K0 of a quotient B to K1 of an ideal I. We show if a K0 element is realized as a homomorphism from qC to B then its boundary is realized as a unitary in the unitization of I. The picture we obtain of the exponential map is based on a projective C*-algebra P that is universal for a set of relations slightly weaker than the relations that define qC. A new, shorter proof of the semiprojectivity of qC is described. Smoothing questions related the relations for qC are addressed.Comment: 11 pages. Added a result about the boundary map in K-theor

Fermi Surface of KFe2_2As2_2 from Quantum Oscillations in Magnetostriction

We present a study of the Fermi surface of KFe$_2$As$_2$ single crystals. Quantum oscillations were observed in magnetostriction measured down to 50 mK and in magnetic fields $H$ up to 14 T. For $H \parallel c$, the calculated effective masses are in agreement with recent de Haas-van Alphen and ARPES experiments, showing enhanced values with respect to the ones obtained from previous band calculations. For $H \parallel a$, we observed a small orbit at a cyclotron frequency of 64 T, characterized by an effective mass of $\sim 0.8 m_e$, supporting the presence of a three-dimensional pocket at the Z-point.Comment: SCES Conference, Tokyo 201

Leistungen und Entwicklung von Öko- Milchviehbetrieben mit geringem Kraftfuttereinsatz in Baden-Württemberg

The aim of this study was the analysis of dairy farms in Baden-Württemberg producing milk without or with only a little amount of concentrate. 12 biological managed farms have been visited and consulted by questionnaire in 2010. Also the results of milk yield testing have been examined. Economic calculations were run for a comparison to conventionally working dairy farms. In 2015 the results were for 10 of these farms updated. Since 2010 the structure of the farms remained almost unchanged (number of cows, milk yield, cultivated area). The proportion of pasture from grassland increased from 45 to 53%. The ecological-low input drived production system leads to better conditions for profitable milk production compared to conventional dairy farms

Disordered Topological Insulators via C∗C^*-Algebras

The theory of almost commuting matrices can be used to quantify topological obstructions to the existence of localized Wannier functions with time-reversal symmetry in systems with time-reversal symmetry and strong spin-orbit coupling. We present a numerical procedure that calculates a Z_2 invariant using these techniques, and apply it to a model of HgTe. This numerical procedure allows us to access sizes significantly larger than procedures based on studying twisted boundary conditions. Our numerical results indicate the existence of a metallic phase in the presence of scattering between up and down spin components, while there is a sharp transition when the system decouples into two copies of the quantum Hall effect. In addition to the Z_2 invariant calculation in the case when up and down components are coupled, we also present a simple method of evaluating the integer invariant in the quantum Hall case where they are decoupled.Comment: Added detail regarding the mapping of almost commuting unitary matrices to almost commuting Hermitian matrices that form an approximate representation of the sphere. 6 pages, 6 figure

Morphisms of Extensions of C*-Algebras: Pushing Forward the Busby Invariant

AbstractWe study completions of diagrams of extensions of C*-algebras in which all three C*-algebras in one of the rows and either the ideal or the quotient in the other are given, along with the three morphisms between them. We find universal solutions to all four of these problems under restrictions of varying severity, on the given vertical maps and describe the solutions in terms of push-outs and pull-backs of certain diagrams. Our characterization of the universal solution to one of the diagrams yields a concrete description of various amalgamated free products. This leads to new results about the K-theory of amalgamated free products, verifying the Cuntz conjecture in certain cases. We also obtain new results about extensions of matricial fieldC*-algebras, verifying partially a conjecture of Blackadar and Kirchberg. Finally, we show that almost commuting unitary matrices can be uniformly approximated by commuting unitaries when an index obstruction vanishes

Classification of graph C*-algebras with no more than four primitive ideals

We describe the status quo of the classification problem of graph C*-algebras with four primitive ideals or less