Test generation and execution are often hampered by the large state spaces of the systems involved. In automata (or transition system) based test algorithms, taking advantage of symmetry in the behavior of specification and implementation may substantially reduce the amount of tests. We present a framework for describing and exploiting symmetries in black box test derivation methods based on fi...

We describe an algorithm which, for any given group G containing an absolutely irreducible, extraspecial normal subgroup, constructs a homomorphism, with nontrivial kernel, from G onto a nontrivial group of permutations or matrices. Thus we reduce the problem of computing with G to two smaller problems. The algorithm, which uses a blend of geometric and black-box techniques, forms part of the b...

This paper presents a view of design methods as process artefacts that can be represented using the function-behaviour-structure (FBS) ontology. This view allows identifying five fundamental approaches to methods: black-box, procedural, artefact-centric, formal and managerial approaches. They all describe method structure but emphasise different aspects of it. Capturing these differences addres...

The grid computing technology permits the coordinate, efficient and effective use of (geographically spread) computational and storage resources with the aim to achieve high performance throughputs for intensive CPU load applications. In this paper we describe the development of a virtual laboratory for environmental applications. The software infrastructure, and the related interface, are deve...

In statistical NLP, Semantic Vector Spaces (SVS) are the standard technique for the automatic modeling of lexical semantics. However, it is largely unclear how these black-box techniques exactly capture word meaning. To explore the way an SVS structures the individual occurrences of words, we use a non-parametric MDS solution of a token-by-token similarity matrix. The MDS solution is visualized...

For complex services composed of many (component) services, logging is an integral middleware aspect, especially for providing transactions and monitoring. In the event of a failure, the log allows us to deduce the cause of failure (diagnosis) and recover by compensating the executed services (atomicity). However, for heterogeneous services with parts of the functionality provided by multiple o...

Timetabling is a typical application of constraint programming whose task is to allocate activities to slots in available resources respecting various constraints like precedence and capacity. In this paper we present a basic concept, a constraint model, and a solution algorithm for interactive timetabling. Interactive timetabling combines automated timetabling (the computer allocates the activ...

We present a “black-box” approach to estimating query cardinality that has no knowledge of query execution plans and data distribution, yet provides accurate estimates. It does so by grouping queries into syntactic families and learning the cardinality distribution of that group directly from points in a high-dimensional input space constructed from the query’s attributes, operators, function a...

We consider the case where inconsistencies are present between a system and its corresponding model, used for automatic verification. Such inconsistencies can be the result of modeling errors or recent modifications of the system. Despite such discrepancies we can still attempt to perform automatic verification. In fact, as we show, we can sometimes exploit the verification results to assist in...

Kernel functions are typically viewed as providing an implicit mapping of points into a high-dimensional space, with the ability to gain much of the power of that space without incurring a high cost if the result is linearly-separable by a large margin γ. However, the Johnson-Lindenstrauss lemma suggests that in the presence of a large margin, a kernel function can also be viewed as a mapping t...