Criterion for the membership of individual meteors to meteoroid streams presented by Valsecchi et. al. (1999) and Jopek et. al. (1999) is discussed. The authors characterize and use their criterion as a distance function. However, it is not a distance function. Some practical aspects are also discussed. Correct criterion is presented.

The spatial footprint of unconventional (hydraulic fracturing) and conventional oil and gas development in the Marcellus Shale region of the State of Pennsylvania was digitized from high-resolution, ortho-rectified, digital aerial photography, from 2004 to 2010. We used these data to measure the spatial extent of oil and gas development and to assess the exposure of the extant natural resources...

Web 2.0 users conveniently consume content through subscribing to content generators such as Twitter users or news agencies. However, given the number of subscriptions and the rate of the subscription streams, users suffer from the information overload problem. To address this issue, we propose a novel and flexible diversification paradigm to prune redundant posts from a collection of streams. ...

We characterized the structure and composition of unmanaged riparian forests in three river basins in Oregon’s coastal mountains. Our objective was to evaluate stand attributes at three spatial scales: streamside (site), drainage network (stream order), and basin (subregion). Data on basal area, species composition, snag density, canopy cover, and tree regeneration were collected along transect...

Streams and rivers form conspicuous networks on the Earth and are among nature's most effective integrators. Their dendritic structure reaches into the terrestrial landscape and accumulates water and sediment en route from abundant headwater streams to a single river mouth. The prevailing view over the last decades has been that biological diversity also accumulates downstream. Here, we show th...

One of the major features that distinguishes multimedia applications from other traditional applications is the integration of various media streams that have to be presented in a synchronized fashion. This paper presents a set of synchronization algorithms for continuous media streams in a distributed best-eeort system. First, we show how the load variation at the source may lead to an erroneo...

Semiaquatic flies (Diptera, Nematocera) are an ecologically important and species rich group of insects within the boreal and arctic biomes. Community structure, species richness and abundance of semiaquatic flies were studied in three habitat types (aapa mires, springs and headwater streams), totaling 19 study sites, within the subalpine ecoregion of northern boreal Finland. Concordance of sem...