An orchestrated survey of available algorithms and tools for Combinatorial Testing

For functional testing based on the input domain of a functionality, parameters and their values are identified and a test suite is generated using a criterion exercising combinations of those parameters and values. Since software systems are large, resulting in large numbers of parameters and values, a technique based on combinatorics called Combinatorial Testing (CT) is used to automate the process of creating those combinations. CT is typically performed with the help of combinatorial objects called Covering Arrays. The goal of the present work is to determine available algorithms/tools for generating a combinatorial test suite. We tried to be as complete as possible by using a precise protocol for selecting papers describing those algorithms/tools. The 75 algorithms/tools we identified are then categorized on the basis of different comparison criteria, including: the test suite generation technique, the support for selection (combination) criteria, mixed covering array, the strength of coverage, and the support for constraints between parameters. Results can be of interest to researchers or software companies who are looking for a CT algorithm/tool suitable for their needs

Experimenting with Category Partition's 1-way and 2-way test selection criteria

The Category Partition (CP) black-box testing method has shown to be effective in a number of situations. There is however little support for automating its use and little is known about the cost effectiveness of its associated selection criteria. In this paper, we report on a tool to automatically create test fra

Robustness in a distributed storage server for engineering design data with versions

Traditional database management systems have been deemed unsuitable for use in the Computer Aided Engineering environment Object-oriented data models with project management features have been proposed as an alternative. The Distributed Hypothetical Storage System is intended to serve as the underlying storage mechanism for an object-oriented data model. The storage system provides features that are essential to project management such as version histories, alternate data versions, and optimistic concurrency control in a distributed environment This thesis presents a robustness mechanism for DHSS. Three classes of system failure are considered: site failure, communication failure, and media failure. The protocols described here make the system robust in two senses: first, users are provided with continued read access to their data; and second, users are provided with continued write access to their data. The traditional approach of data replication is used to support continued read access. However, traditional systems support no write access or highly restricted write access in the event of a failure. The DHSS robustness mechanism supports continued write access for all visible data by allowing the execution of possibly conflicting write requests and attempting to merge or resolve the results at a later time if they are indeed conflicting. The resolution protocol requires one exchange of information among the communicating sites followed by unilateral calculation to resolve all conflicts existing among that set of sites. It is essential that the resolution be mutually consistent among the set of communicating sites. It is shown that the robustness protocols produce a mutually consistent resolution of conflicting requests

A Novel Tree Structure for Pattern Matching in Biological Sequences

This dissertation proposes a novel tree structure, Error Tree (ET), to more efficiently solve the Approximate Pattern Matching problem, a fundamental problem in bioinformatics and information retrieval. The problem involves different matching measures such as the Hamming distance, edit distance, and wildcard matching. The input is usually a text of length n over a fixed alphabet of size Σ, a pattern P of length m, and an integer k. The output is those subsequences in the text that are at a distance ≤ k from P by Hamming distance, edit distance, or wildcard matching. An immediate application of the approximate pattern matching is the Planted Motif Search, an important problem in many biological applications such as finding promoters, enhancers, locus control regions, transcription factors, etc. The (l, d)-Planted Motif Search is defined as the following: Given n sequences over an alphabet of size Σ, each of length m, and two integers l and d, find a motif M of length l, where in each sequence there is at least an l-mer (substring of length l) at a Hamming distance of ≤ d from M. Based on the ET structure, our algorithm ET-Motif solves this problem efficiently in time and space. The thesis also discusses how the ET structure may add efficiency when it comes to Genome Assembly and DNA Sequence Compression. Current high-throughput sequencing technologies generate millions or billions of short reads (100-1000 bases) that are sequenced from a genome of millions or billions bases long. The De novo Genome Assembly problem is to assemble the original genome as long and accurate as possible. Although high quality assemblies can be obtained by assembling multiple paired-end libraries with both short and long insert sizes, the latter is costly to generate. Moreover, the recent GAGE-B study showed that a remarkably good assembly quality can be obtained for bacterial genomes by state-of-the-art assemblers run on a single short-insert library with a very high coverage. This thesis introduces a novel Hierarchical Genome Assembly (HGA) method that takes further advantage of such high coverage by independently assembling disjoint subsets of reads, combining assemblies of the subsets, and finally re-assembling the combined contigs along with the original reads. We empirically evaluate this methodology for eight leading assemblers using seven GAGE-B bacterial datasets consisting of 100bp Illumina HiSeq and 250bp Illumina MiSeq reads with coverage ranging from 100x-∼200x. The results show that HGA leads to a significant improvement in the quality of the assembly for all evaluated assemblers and datasets. Still, the problem involves a major step which is overlapping the ends of the reads together and allowing few mismatches (i.e. the approximate matching problem). This requires computing the overlaps between the ends of all-against-all reads. The computation of such overlaps when allowing mismatches is intensive. The ET structure may further speed up this step. Lastly, due to the significant amount of DNA data generated by the Next- Generation-Sequencing machines, there is an increasing need to compress such data to reduce the storage space and transmission time. The Huffman encoding that incorporates DNA sequence characteristics proves to better compress DNA data. Different implementations of Huffman trees, centering on the selection of frequent repeats, are introduced in this thesis. Experimental results demonstrate improvement on the compression ratios for five genomes with lengths ranging from 5Mbp to 50Mbp, compared with the use of a standard Huffman tree algorithm. Hence, the thesis suggests an improvement on all DNA sequence compression algorithms that employ the conventional Huffman encoding. Moreover, approximate repeats can be compressed and further improve the results by encoding the Hamming or edit distance between these repeats. However, computing such distances requires additional costs in both time and space. These costs can be reduced by using the ET structure

Proceedings of the International Symposium on Low Cost Housing Problems Related to Urban Renewal and Development

PREFACE TO SECOND EDITION--We are very happy to have a second printing of the Proceedings of the First International Symposium on Low-Cost Housing Problems Related to Urban Renewal and Development. The rather quick and large demand of this publication proved to us, once more, the importance and timeliness of the concern on the topic of housing technology and production. The contributions from eighteen nations painted a real picture of housing conditions and needs around the world. The fifty-one technical papers included in this volume have been selected intentionally in various aspects of housing to draw a complete and meaningful picture of the topic. This is imperative since a successful housing project cannot be isolated from the social and economic environment. All pertinent factors related to housing should be defined and considered in the planning process. An INTEGRATED SYSTEMS APPROACH is the only means to secure success in any housing project. This will be the theme of the Second International Symposium to be held on April 24-25, 1972. The encouragement and positive comments which were conveyed to me after the conference are the foundations of this second Symposium. The faculty of the Civil Engineering Department and the members of the Extension Division should be cited for their contributions and cooperation for the success of this first Symposium.Rolla, MissouriOktay UralOctober, 197