Aliya Ibragimova. CiteWise — The Citation Search Engine. Masters thesis, University of Bern, June 2015. Details.
Nowadays the number of documents in the World Wide Web grows at extremely fast rate. Tools that can facilitate information retrieval (IR) present a particular interest in the modern world. We believe that considering meta information helps us to build enhanced search systems that can facilitate IR. Particularly, we target an IR task for scientific articles. We consider citations in scientific articles to be important text blocks summarizing or judging previous scientific findings, assisting in creating new scientific work. We propose CiteWise, a software system that automatically extracts, indexes and aggregates citations from collections of scientific articles in a PDF format. We evaluated the capabilities of CiteWise by conducting user evaluation experiments that compare it with alternative approaches. In the first set of experiments, we measured the efficiency of our system, i.e. how fast users can find relevant results in comparison with Google Scholar. We found that CiteWise performs equally well as Google Scholar. Secondly, we developed a citation aggregation feature to create automatic summaries of scientific articles and asked domain experts to evaluate summaries created by CiteWise and TextRank algorithms. We found that CiteWise outperforms TextRank algorithm in generating article summaries.
Nevena Milojković, Andrea Caracciolo, Mircea Lungu, Oscar Nierstrasz, David Röthlisberger, and Romain Robbes. Polymorphism in the Spotlight: Studying its Prevalence in Java and Smalltalk. In Proceedings of International Conference on Program Comprehension (ICPC 2015), p. 1—10, 2015. To appear. Details.
Subtype polymorphism is a cornerstone of object-oriented programming. By hiding variability in behavior behind a uniform interface, polymorphism decouples clients from providers and thus enables genericity, modularity and extensi- bility. At the same time, however, it scatters the implementation of the behavior over multiple classes thus potentially hampering program comprehension. The extent to which polymorphism is used in real programs and the impact of polymorphism on program comprehension are not very well understood. We report on a preliminary study of the prevalence of polymorphism in several hundred open source software systems written in Smalltalk, one of the oldest object-oriented programming languages, and in Java, one of the most widespread ones. Although a large portion of the call sites in these systems are polymorphic, a majority have a small number of potential candidates. Smalltalk uses polymorphism to a much greater extent than Java. We discuss how these findings can be used as input for more detailed studies in program comprehension and for better developer support in the IDE.
Leonel Merino, Mircea Lungu, and Oscar Nierstrasz. Explora: Infrastructure for Scaling Up Software Visualisation to Corpora. In SATToSE’14: Post-Proceedings of the 7th International Seminar Series on Advanced Techniques & Tools for Software Evolution, 1354, CEUR Workshop Proceedings (CEUR-WS.org), 2015. http://ceur-ws.org/Vol-1354/. Details.
Visualisation provides good support for software analysis. It copes with the intangible nature of software by providing concrete representations of it. By reducing the complexity of software, visualisations are especially useful when dealing with large amounts of code. One domain that usually deals with large amounts of source code data is empirical analysis. Although there are many tools for analysis and visualisation, they do not cope well software corpora. In this paper we present Explora, an infrastructure that is specifically targeted at visualising corpora. We report on early results when conducting a sample analysis on Smalltalk and Java corpora.
Roger Stebler. Evaluating the dynamic behavior of Smalltalk applications. Bachelor’s thesis, University of Bern, April 2015. Details.
Since Smalltalk is a dynamically typed programming language it remain agnostic to variable types at compile time, and only take them into account at runtime. This gives more freedom to the developer, as one variable can take on radically different types during program execution. Lack of understanding of dynamic behavior of Smalltalk applications can lead to misleading conclusions about the presents of dynamic features such as duck typing. By instrumenting Smalltalk source code and tracking the different types that variables receive, we concluded that duck-typed variables account for around 1% of total variables. We gather this information using our tool named VariableTracker. We also present an analysis of usage patterns of duck-typed variables from our collected data.
Camille Teruel, Erwann Wernli, Stéphane Ducasse, and Oscar Nierstrasz. Propagation of Behavioral Variations with Delegation Proxies. In Shigeru Chiba, Éric Tanter, Erik Ernst, and Robert Hirschfeld (Ed.), Transactions on Aspect-Oriented Software Development XII, Lecture Notes in Computer Science 8989 p. 63-95, Springer Berlin Heidelberg, 2015. Details.
Scoping behavioral variations to dynamic extents is useful to support non-functional concerns that otherwise result in cross-cutting code. Unfortunately, such forms of scoping are difficult to obtain with traditional reflection or aspects. We propose delegation proxies, a dynamic proxy model that supports behavioral intercession through the interception of various interpretation operations. Delegation proxies permit different behavioral variations to be easily composed together. We show how delegation proxies enable behavioral variations that can propagate to dynamic extents. We demonstrate our approach with examples of behavioral variations scoped to dynamic extents that help simplify code related to safety, reliability, and monitoring.