Airplane take-off performance indicator Patent

Aircraft instrument for indicating malfunctions during takeof

Twelve Theses on Reactive Rules for the Web

Reactivity, the ability to detect and react to events, is an essential functionality in many information systems. In particular, Web systems such as online marketplaces, adaptive (e.g., recommender) systems, and Web services, react to events such as Web page updates or data posted to a server. This article investigates issues of relevance in designing high-level programming languages dedicated to reactivity on the Web. It presents twelve theses on features desirable for a language of reactive rules tuned to programming Web and Semantic Web applications

NASA's supercomputing experience

A brief overview of NASA's recent experience in supercomputing is presented from two perspectives: early systems development and advanced supercomputing applications. NASA's role in supercomputing systems development is illustrated by discussion of activities carried out by the Numerical Aerodynamical Simulation Program. Current capabilities in advanced technology applications are illustrated with examples in turbulence physics, aerodynamics, aerothermodynamics, chemistry, and structural mechanics. Capabilities in science applications are illustrated by examples in astrophysics and atmospheric modeling. Future directions and NASA's new High Performance Computing Program are briefly discussed

Railway regulation in 19th Century Britain: the economic rationale and legacy of Gladstone and Chadwick

This paper examines the economic rationale of the ideas of Gladstone & Chadwick on railway regulation and the legacy of their ideas. In 1844 Gladstone proposed and implemented what we would now call price and quantity regulation whereas in 1859 Chadwick proposed competition "for the field", i.e. the establishment of a temporary monopoly or franchise, for a given period. The thinking of Gladstone had been influenced by the classical school of economic thought, most notably J R McCulloch, whilst Chadwick had ideas influenced by his association with Jeremy Bentham and John Stuart Mill. This ideas still impact today; the basic pattern of price and some quantity regulation inaugurated by Gladstone was not abolished until the 1960 Transport Act whilst Chadwicks idea of temporary licenses or franchises came back into vogue when the railways were privatised in 1997.Britain, nineteenth century, railway regulation, classical school, J R McCulloch, Edwin Chadwick, John Stuart Mill

Metric dimension of dual polar graphs

A resolving set for a graph $\Gamma$ is a collection of vertices $S$, chosen so that for each vertex $v$, the list of distances from $v$ to the members of $S$ uniquely specifies $v$. The metric dimension $\mu(\Gamma)$ is the smallest size of a resolving set for $\Gamma$. We consider the metric dimension of the dual polar graphs, and show that it is at most the rank over $\mathbb{R}$ of the incidence matrix of the corresponding polar space. We then compute this rank to give an explicit upper bound on the metric dimension of dual polar graphs.Comment: 8 page

On the metric dimension of Grassmann graphs

The {\em metric dimension} of a graph $\Gamma$ is the least number of vertices in a set with the property that the list of distances from any vertex to those in the set uniquely identifies that vertex. We consider the Grassmann graph $G_q(n,k)$ (whose vertices are the $k$-subspaces of $\mathbb{F}_q^n$, and are adjacent if they intersect in a $(k-1)$-subspace) for $k\geq 2$, and find a constructive upper bound on its metric dimension. Our bound is equal to the number of 1-dimensional subspaces of $\mathbb{F}_q^n$.Comment: 9 pages. Revised to correct an error in Proposition 9 of the previous versio

Study made of ductility limitations of aluminum-silicon alloys

Study of the relation between microstructure and mechanical properties of aluminum-silicon alloys determines the cause of the variations in properties resulting from differences in solidification rate. It was found that variations in strength are a consequence of variations in ductility and that ductility is inversely proportional to dendrite cell size