Worcester Polytechnic Institute

About: Worcester Polytechnic Institute is a education organization based out in Worcester, Massachusetts, United States. It is known for research contribution in the topics: Computer science & Population. The organization has 6270 authors who have published 12704 publications receiving 332081 citations. The organization is also known as: WPI.

Modular verification of collaboration-based software designs

Abstract: Most existing modular model checking techniques betray their hardware roots: they assume that modules compose in parallel. In contrast, collaboration-based software designs, which have proven very successful in several domains, are sequential in the simplest case. Most interesting collaboration-based designs are really quasi-sequential compositions of parallel compositions. These designs demand and inspire new verification techniques. This paper presents algorithms that exploit the software's modular decomposition to verify collaboration-based designs. Our technique can verify most properties locally in the collaborations; we also characterize when a global state space construction is unavoidable. We have validated our proposal by testing it on several designs.

Reasoning with Design Rationale

Abstract: Design Rationale (DR) consists of the decisions made during the design process and the reasons behind them. Because it offers more than just a “snapshot” of the final design decisions, DR is invaluable as an aid for revising, maintaining, documenting, evaluating, and learning the design. Much work has been performed on how DR can be captured and represented but not as much on how it can be used. In this paper, we investigate the use of DR by building InfoRat, a system that inferences over a design’s rationale in order to detect inconsistencies and to assess the impact of changes.

Navigating hierarchies with structure-based brushes

Abstract: Interactive selection is a critical component in exploratory visualization, allowing users to isolate subsets of the displayed information for highlighting, deleting, analysis, or focussed investigation. Brushing, a popular method for implementing the selection process, has traditionally been performed in either screen space or data space. We introduce the concept of a structure-based brush, which can be used to perform selection in hierarchically structured data sets. Our structure-based brush allows users to navigate hierarchies by specifying focal extents and level-of-detail on a visual representation of the structure. Proximity-based coloring, which maps similar colors to data that are closely related within the structure, helps convey both structural relationships and anomalies. We describe the design and implementation of our structure-based brushing tool. We also validate its usefulness using two distinct hierarchical visualization techniques, namely hierarchical parallel coordinates and tree-maps.

An algorithmic version of the blow-up lemma

Abstract: Recently we developed a new method in graph theory based on the regularity lemma. The method is applied to find certain spanning subgraphs in dense graphs. The other main general tool of the method, besides the regularity lemma, is the so-called blow-up lemma (Komlos, Sarkozy, and Szemeredi [Combinatorica,17, 109–123 (1997)]. This lemma helps to find bounded degree spanning subgraphs in e-regular graphs. Our original proof of the lemma is not algorithmic, it applies probabilistic methods. In this paper we provide an algorithmic version of the blow-up lemma. The desired subgraph, for an n-vertex graph, can be found in time O(nM(n)), where M(n)=O(n2.376) is the time needed to multiply two n by n matrices with 0, 1 entires over the integers. We show that the algorithm can be parallelized and implemented in NC5. © 1998 John Wiley & Sons, Inc. Random Struct. Alg., 12, 297–312, 1998