Extracting Build Changes with BUILDDIFF

Build systems are an essential part of modern software engineering projects. As software projects change continuously, it is crucial to understand how the build system changes because neglecting its maintenance can lead to expensive build breakage. Recent studies have investigated the (co-)evolution of build configurations and reasons for build breakage, but they did this only on a coarse grained level. In this paper, we present BUILDDIFF, an approach to extract detailed build changes from MAVEN build files and classify them into 95 change types. In a manual evaluation of 400 build changing commits, we show that BUILDDIFF can extract and classify build changes with an average precision and recall of 0.96 and 0.98, respectively. We then present two studies using the build changes extracted from 30 open source Java projects to study the frequency and time of build changes. The results show that the top 10 most frequent change types account for 73% of the build changes. Among them, changes to version numbers and changes to dependencies of the projects occur most frequently. Furthermore, our results show that build changes occur frequently around releases. With these results, we provide the basis for further research, such as for analyzing the (co-)evolution of build files with other artifacts or improving effort estimation approaches. Furthermore, our detailed change information enables improvements of refactoring approaches for build configurations and improvements of models to identify error-prone build files.Comment: Accepted at the International Conference of Mining Software Repositories (MSR), 201

Resistance versus Transformation: Exploring the Transformative Potential of High-Impact Service-Learning Experiences

Guided by the Social Change Paradigm of Service (Morton, 1995), this case study focuses on the service-learning experience emerging out of the partnership between the Community Development Program at Brescia University College and the Regional HIV/AIDS Connection (RHAC) in London, Ontario, Canada. Critical to the experience is a relationship based on trust and mutual learning between the professor and community partner. Service-learning is conceptualized as a transformational learning model that has as its foundation, Cranton’s (2002) facets of transformative learning. Particularly important to this model are activating events. When an activating event occurs that does not fit with a student’s expectation of how things should be, two outcomes are possible: resistance or transformation. When combined with personal reflection and dialogue, the sharing of lived experience by a person connected to RHAC has been a powerful activator for moving students from being resistant towards personal transformation

Resistance versus Transformation: Exploring the Transformative Potential of High-Impact Service-Learning Experiences

Guided by the Social Change Paradigm of Service (Morton, 1995), this case study focuses on the service-learning experience emerging out of the partnership between the Community Development Program at Brescia University College and the Regional HIV/AIDS Connection (RHAC) in London, Ontario, Canada. Critical to the experience is a relationship based on trust and mutual learning between the professor and community partner. Service-learning is conceptualized as a transformational learning model that has as its foundation, Cranton’s (2002) facets of transformative learning. Particularly important to this model are activating events. When an activating event occurs that does not fit with a student’s expectation of how things should be, two outcomes are possible: resistance or transformation. When combined with personal reflection and dialogue, the sharing of lived experience by a person connected to RHAC has been a powerful activator for moving students from being resistant towards personal transformation

Potential maps, Hardy spaces, and tent spaces on special Lipschitz domains

Suppose that Ω is the open region in ℝn above a Lipschitz graph and let d denote the exterior derivative on ℝn. We construct a convolution operator T which preserves support in Ω is smoothing of order 1 on the homogeneous function spaces, and is a potential map in the sense that dT is the identity on spaces of exact forms with support in Ω. Thus if f is exact and supported in Ω then there is a potential u, given by u = T f, of optimal regularity and supported in Ω, such that du = f. This has implications for the regularity in homogeneous function spaces of the de Rham complex on Ω with or without boundary conditions. The operator T is used to obtain an atomic characterisation of Hardy spaces Hp of exact forms with support in Ω when n/(n + 1) < p ≤ 1. This is done via an atomic decomposition of functions in the tent spaces Tp(ℝn _ ℝ+) with support in a tent T(Ω) as a sum of atoms with support away from the boundary of Ω . This new decomposition of tent spaces is useful, even for scalar valued functions

A Unique Tryptophan C‐Prenyltransferase from the Kawaguchipeptin Biosynthetic Pathway

Acknowledgements This work was supported by funding of the Academy of Finland (259505), Helsinki University Research grant (490085) and ESCMID grant (4720572) to D.P.F., University of Pittsburgh Central Research Development Fund to X.L., Technology Strategy Board grant (131181) to W.H., M.J. and J.H.N. National Programme of Sustainability I of the Ministry of Education of the Czech Republic I grant (LO1416) to T.G.Peer reviewedPostprin