then consider the bene ts of and describe, a more formal approach. We re-visit the scoping phase, and discuss the role of formal languages and techniques in the specification, implementation and evaluation of ontologies. Finally, we review the state of the art and practice in this emerging field,

Caching introduces the overbead and complexity of ensur-ing consistency, reducing some of its performance bene-fits. In a distributed system, caching must deal,wit.h the additional complications of communication and host fail-ures. Leases are proposed as a time-based mechanism that provides

Chronic heart failure is a syndrome characterized by left ventricular dysfunction, reduced exercise toler-ance, impaired quality of life, and a markedly short-w xened life-expectancy 1,2. A substantial proportion of

During 1984–1996, welfare and tax policy were changed to encourage work by single mothers. The Earned Income Tax Credit was expanded, welfare bene�ts were cut, welfare time limits were added, and welfare cases were terminated. Medicaid for the working poor was expanded, as were training programs

. We present a model for analyzing software rejuvenation in such continuously-running applications and express downtime and costs due to downtime during rejuvneation in terms of the parameters in that model. Threshold conditions for rejuvenation to be bene cial are also derived. We implemented

This paper has bene…tted from the comments and criticisms of participants at the 2000 EEA Meeting in Bolzano, at conferences in Heidelberg and in Toulouse, and at various seminars in Vienna, Rotterdam, Lausanne and Paris. We are in particular indebted to P.Aghion, C.Shapiro and J.Tirole. Remaining

The Benes network is a rearrangeable nonblocking network which can realize any arbitrary permutation. Overall, the r-dimensional Benes network connects 2 r inputs to 2 r outputs through 2r \Gamma 1 levels of 2 \Theta 2 switches. Each level of switches consists of 2 r\Gamma1 switches

We consider a bene t model for on-line preemptive scheduling. In this model jobs arrive at the on-line scheduler at their release time. Each job arrives with its own execution time and bene t function. The ow time of a job is the time that passes from its release to its completion. The bene

on the application of knowledge about the expected timewise-renement abilities of reasoning strategies to balance the bene ts of additional computation with the costs of acting with a partial result. We dis-cuss the benets of applying decision theory to control the solution of dicult problems given limitations

A network is called nonblocking if every unused input can be connected by a path through unused edges to any unused output, regardless of which inputs and outputs have been already connected. The Benes network of dimension n is shown to be strictly nonblocking if only a suitable chosen fraction