Physical Sciences and Mathematics Commons^™

The In Situ Passive Acoustic Measurement Of Shingle Movement Under Waves And Currents: Instrument (Tosca) Development And Preliminary Results, George Voulgaris, Michael Wilkin, Michael Collins

George Voulgaris

An instrumented platform (TOSCA) is described for monitoring coarse-grained sediment transport in high (wave and tidal) energy environments. The system consists of a number of sensors which measure: instantaneous current velocities at three levels; sea surface elevation; and self-generated noise (SGN) caused by intercollision of particles in transit. SGN is related to transport rates, on the basis of laboratory calibration; this, in turn, allows a correlation with simultaneous near-bed shear stress to be established. During the field measurements, PC-based real-time data transmission is realised through the use of a (buoyed) radio telemetry system.

TOSCA has been deployed in eastern Christchurch …

Nanosubharmonics: The Dynamics Of Small Nonlinear Contacts, Nancy Burnham, A Kulik, G Gremaud, Gad Briggs

Nancy A. Burnham

We observed the generation of subharmonics and chaos in a nanometer-sized mechanical contact. To first order, the behavior matches that of macroscopic systems, with some intriguing secondary differences. As the occurrence of periodic behavior (subharmonics) is related to the coefficient of restitution, it may be possible to image local energy dissipation with nanometer resolution.

Categories Of Fuzzy Sets With Values In A Quantale Or Projectale, Lawrence Stout

Lawrence N. Stout

Properties of the lattice L are reflected in the properties of the categories Set(L), Set(L)/(A,α), and the lattice U(A, α). The lattices U(A,α) best reflect the structures on the lattice if the structure is inherited by closed down segments and direct products. Operations at the level of the slice categories require distributivity too. The first object of this paper is to see how the additional structures given by an associative operation & which distributes over sups and hence has a right adjoint (a quantale in the sense of Rosenthal [7]) shows up at the three different levels for fuzzy sets. …

Asymptotic Behavior Of Solutions Of Asymptotically Constant Coefficient System Of Linear Differential Equations, William F. Trench

William F. Trench

No abstract provided.