We formalize the notion of important extrema of a time series, that is, its major minima and maxima; analyze basic mathematical properties of important extrema; and apply these results to the problem of time-series compression. First, we define numeric importance levels of extrema in a series, and present algorithms for identifying major extrema and computing their importances. Then, we give a ...

When a sounding tuning fork is brought close to the ear, and rotated about its long axis, four distinct maxima and minima are heard. However, when the same tuning fork is rotated while being held at arm’s length from the ear only two maxima and minima are heard. Misconceptions concerning this phenomenon are addressed and the fundamental mode of the fork is described in terms of a linear quadrup...

In this letter we report Brillouin scattering measurements on methyl-methacrylate (MMA) gels crosslinked with varying amounts of ethylene-dimethacrylate (EDMA). We find that the k dependence of the phase velocity changes on increasing the cross-link content. For higher concentrations of crosslink we observe maxima and minima in the k dependence of the phase velocity. We associate these minima a...

This report presents the design and implementation of an on-line cursive letter recognizer using sequences of local extrema. Recognition tests were performed on single writer's data. The results for top five alternatives exceeded 90% (Table 4). The matching is performed in three stages: • letter size normalisation (Figure 1); • limiting the recognition domain using sequences of local extrema an...

We describe a technique for fast compression of time series and indexing of compressed series. We have tested it on three data sets: stock prices, air and sea temperatures, and wind speeds.

India jaikumar~tcs.tifr.res.in We show non-triviallower bounds for several prefix problems in the CReW PRAM model. Our main result is an O( a( n)) lower bound for the chaining problem, matching the previously known upper bound. We give a reduction to show that the same lower bound applies to a parenthesis matching problem, again matching the previously known upper bound. We also give reductions...

16 17 It is widely assumed that the boundary layer above the core is the source of intraplate volcanoes 18 such as Hawaii, Samoa and Yellowstone and that the sub-plate boundary layer at the top of the 19 mantle is thin and entirely subsolidus. In fact, this layer is thicker and has higher expansivity, 20 buoyancy and insulating power than the lower one, and may have higher potential temperature...