TIng a per'son's proximale environment is most important for this form of com-puting since the interesting part of the world around us is what we can see, hear, and touch. In this paper we define context-aware computing, and describe four cal-egones of conteL·t-aware applications: proximate

unique challenges in the design of unattended autonomous sensor networks. These challenges lead us to hypothesize that sensor network coordination applications may need to be structured differently from traditional net-work applications. In particular, we believe that localized algorithms (in which

Reliability at massive scale is one of the biggest challenges we face at Amazon.com, one of the largest e-commerce operations in the world; even the slightest outage has significant financial consequences and impacts customer trust. The Amazon.com platform, which provides services for many web

Understanding program behavior is at the foundation of computer architecture and program optimization. Many pro-grams have wildly different behavior on even the very largest of scales (over the complete execution of the program). This realization has ramifications for many architectural and com

strongly resembles, in a manner analofunctions of novel genes are needed to ensure rapid gous to fingerprinting. An appealing aspect of this approgress from genome sequence to directed experiproach is that it should be equally effective at determinmentation and applications. A similar need exists for ing

Abstract-The description of a novel type of rn-gram language model is given. The model offers, via a nonlinear recursive procedure, a com-putation and space efficient solution to the problem of estimating prob-abilities from sparse data. This solution compares favorably to other proposed methods

Structured peer-to-peer overlay networks provide a sub-strate for the construction of large-scale, decentralized applications, including distributed storage, group com-munication, and content distribution. These overlays are highly resilient; they can route messages correctly even when a large

and thereby removing the associated com-putational complexity. The scheme i s based on the adoption of an internally generated virtual time as the index of work progress, hence the name self-clocked fair queueing. W e prove that the scheme possesses the desired fairness property and i s nearly optimal

Schema matching is the task of finding semantic correspondences between elements of two schemas. It is needed in many database applications, such as integration of web data sources, data warehouse loading and XML message mapping. To reduce the amount of user effort as much as possible

Shadowing has historically been used to increase the intelligibility of scenes in electron micros-copy and aerial survey. Various methods have been published for the determination of shadows in com-puter synthesized scenes. The display of shadows may make the shape and relative position of objects