We use soft heaps to obtain simpler optimal algorithms for selecting the k-th smallest item, and the set of k smallest items, from a heap-ordered tree, from a collection of sorted lists, and from X + Y , where X and Y are two unsorted sets. Our results match, and in some ways extend and improve, classical results of Frederickson (1993) and Frederickson and Johnson (1982). In particular, for sel...

The content of many communication services depend on the context, such as the user’s location. We describe a ’service’ URN that allows to register such context-dependent services that can be resolved in a distributed manner. Schulzrinne Expires September 6, 2006 [Page 1] Internet-Draft Service URN March 2006

Advances in sensing and data gathering technologies have resulted in an explosion in the volume of data that is being generated, processed, and archived. In particular, this information overload calls for new methods for querying large spatial datasets, since users are often not interested in merely retrieving a list of all data items satisfying a query, but would, instead, like a more informat...

Recently, it has been emphasized that the possibility theory framework allows us to dis­ tinguish between i) what is possible because it is not ruled out by the available knowledge, and ii) what is possible for sure. This distinc­ tion may be useful when representing knowl­ edge, for modelling values which are not im­ possible because they are consistent with the available knowledge on the one ...

Then, two points p, q of an orthogonal polygon P are s-visible from one another if there exists a stair ase path from p to q that lies in P (Figure 1(a) shows two su h points p and q). The set of points that are s-visible from a point p form the s-visibility polygon of p. The s-kernel of P is the (possibly empty) set of points of P whose s-visibility polygon is equal to P , i.e., the set of poi...

This article is concerned with the social organization of mediation in learning environments. It seeks to further articulate the sociocultural notion of mediation in sociointeractional terms, combining insights from the sociocultural approach to cognition and the microinteractionist, especially ethnomethodological approach to social activities.Amicroanalysisofmediation incommunicative2nd-langua...

We report the theoretical comparison of the omnidirectional photonic bandgap (OPBG) of one-dimensional dielectric photonic structures, using three different refractive index profiles: sinusoidal, Gaussian, and Bragg. For different values of physical thickness (PT) and optical thickness (OT), the tunability of the OPBG of each profile is shown to depend on the maximum/minimum refractive indices....

Despite intensive research during the past decade on the effects of alien species, invasion science still lacks the capacity to accurately predict the impacts of those species and, therefore, to provide timely advice to managers on where limited resources should be allocated. This capacity has been limited partly by the context-dependent nature of ecological impacts, research highly skewed towa...