Partial redundancy elimination (PRE) is a code optimization algorithm that simultaneously performs common sub-expression and loop-invariant motion. Traditional PREs analyze the entire program eliminate redundancies. By contrast, demand-driven PRE (DDPRRE) proposed as an to only part of determine whether each expression redundant by query propagation. The previous DDPRE reduces analysis time bec...

Traditionally, vertical integration has concerned industrial economists only insofar as it affects market outcomes, particularly prices. This paper considers reverse causality, from prices – and more generally, from demand – to integration in a model of a dynamic oligopoly. If integration is costly but enhances productive efficiency, then a trend of rising prices and increasing integration coul...

Many clustering protocols for mobile ad hoc networks (MANETs) have been proposed in the literature. With only one exception so far [1], all these protocols are proactive, thus wasting bandwidth when their function is not currently needed. To reduce the signalling traffic load, reactive clustering may be employed. We have developed a clustering protocol named “OnDemand Group Mobility-Based Clust...

To e ectively parallelize real programs, parallelizing compilers need powerful symbolic analysis techniques [13, 6]. In previous work we have introduced an algorithm called range propagation [4] that provides such capabilities. Range propagation has been implemented in Polaris, a parallelizing Fortran compiler being developed at the University of Illinois [7]. Because the algorithm is relativel...

Many researchers have proposed programming languages that support incremental computation (IC), which allows programs to be efficiently re-executed after a small change to the input. However, existing implementations of such languages have two important drawbacks. First, recomputation is oblivious to specific demands on the program output; that is, if a program input changes, all dependencies w...

We discuss how to perform symbolic execution of large programs in a manner that is both compositional (hence more scalable) and demand-driven. Compositional symbolic execution means finding feasible interprocedural program paths by composing symbolic executions of feasible intraprocedural paths. By demand-driven, we mean that as few intraprocedural paths as possible are symbolically executed in...

When the user input is first received by the erver, th system performs a string match comparing the user's answer to pre-stored answers. Each pre-stored answer is accompanied by a previously computed analysis for student model updates. Storing multiple answers allows for freer student input and, at an introductory level, involves little extra work. At an advanced level where exercises become ev...