that the relational approach can handle most (but not all) of the semantics of semi-structured queries over XML data, but is likely to be effective only in some cases. We identify the causes for these limitations and propose certain extensions to the relational

over the last several years, particularly distributed locking and recovery technology. To date it has been a matter of conjecture how well these ideas scale. We have had the opportunity to test those limits in the context of a product that runs on the largest systems in existence. While in many cases

Abstract — Disruption-tolerant networks (DTNs) attempt to route network messages via intermittently connected nodes. Routing in such environments is difficult because peers have little information about the state of the partitioned network and transfer opportunities between peers are of limited

for example), or it can come from the execution of a statically compiled native binary. This paper evaluates the Dynamo system in the latter, more challenging situation, in order to emphasize the limits, rather than the potential, of the system. Our experiments demonstrate that even statically optimized

or chocolates or to undertake optional class essay assignments when offered a limited array of 6 choices rather than a more extensive array of 24 or 30 choices. Moreover, participants actually reported greater subsequent satisfaction with their selections and wrote better essays when their original set

process, the resulting student population of each academy, and the differing Career Academy cultures and institutional mechanisms. This article sug-gests that Career Academies constitute a potentially successful school reform strat-egy, despite their limitations. I cast the same image that Victor’s story

This paper argues that both unequal opportunity and social mobility are necessary implications of an efficient societal arrangement when incentives must be provided. 1.

of maintenance activities within the scheduling horizon are considered. Moreover, in presence of opportunities with limited durations in which some maintenance activities could be executed with reduced maintenance costs, the present paper proposes a new algorithm to optimally update online the grouping

Pervasive micro-sensing and actuation may revolutionize the way in which we understand and manage complex physical systems: from airplane wings to complex ecosystems. The capabilities for detailed physical monitoring and manipulation offer enormous opportunities for almost every scientific

. The rated functioning zones are then shifted to-wards their limits, which induces to run the drive very often at voltage and current limits. Finally, the necessity of fault tolerant characteristics associated to cost constraints leads to the choice of intrinsic fault-tolerant systems, avoiding then the use