Translating Video Recordings of Mobile App Usages into Replayable Scenarios

Screen recordings of mobile applications are easy to obtain and capture a wealth of information pertinent to software developers (e.g., bugs or feature requests), making them a popular mechanism for crowdsourced app feedback. Thus, these videos are becoming a common artifact that developers must manage. In light of unique mobile development constraints, including swift release cycles and rapidly evolving platforms, automated techniques for analyzing all types of rich software artifacts provide benefit to mobile developers. Unfortunately, automatically analyzing screen recordings presents serious challenges, due to their graphical nature, compared to other types of (textual) artifacts. To address these challenges, this paper introduces V2S, a lightweight, automated approach for translating video recordings of Android app usages into replayable scenarios. V2S is based primarily on computer vision techniques and adapts recent solutions for object detection and image classification to detect and classify user actions captured in a video, and convert these into a replayable test scenario. We performed an extensive evaluation of V2S involving 175 videos depicting 3,534 GUI-based actions collected from users exercising features and reproducing bugs from over 80 popular Android apps. Our results illustrate that V2S can accurately replay scenarios from screen recordings, and is capable of reproducing $\approx$ 89% of our collected videos with minimal overhead. A case study with three industrial partners illustrates the potential usefulness of V2S from the viewpoint of developers.Comment: In proceedings of the 42nd International Conference on Software Engineering (ICSE'20), 13 page

Energy bursts in fiber bundle models of composite materials

As a model of composite materials, a bundle of many fibers with stochastically distributed breaking thresholds for the individual fibers is considered. The bundle is loaded until complete failure to capture the failure scenario of composite materials under external load. The fibers are assumed to share the load equally, and to obey Hookean elasticity right up to the breaking point. We determine the distribution of bursts in which an amount of energy $E$ is released. The energy distribution follows asymptotically a universal power law $E^{-5/2}$, for any statistical distribution of fiber strengths. A similar power law dependence is found in some experimental acoustic emission studies of loaded composite materials.Comment: 5 pages, 4 fig

Response of CdWO4 crystal scintillator for few MeV ions and low energy electrons

The response of a CdWO4 crystal scintillator to protons, alpha particles, Li, C, O and Ti ions with energies in the range 1 - 10 MeV was measured. The non-proportionality of CdWO4 for low energy electrons (4 - 110 keV) was studied with the Compton Coincidence Technique. The energy dependence of the quenching factors for ions and the relative light yield for low energy electrons was calculated using a semi-empirical approach. Pulse-shape discrimination ability between gamma quanta, protons, alpha particles and ions was investigated.Comment: 20 pages, 8 figs, accepted in Nucl. Instrum. Meth.

Endovascular Management of Juxtarenal and Pararenal Abdominal Aortic Aneurysms: Role of Chimney Technique

The use of chimney technique in endovascular repair of abdominal aortic aneurysms (ChEVAR) has had a secondary role. Although it was first developed in an emergent/urgent setting, the publication of various important studies has helped overcome scepticism towards this technique in elective procedures. This paper reviews current evidence about ChEVAR, focusing on clinical results, technical notes and comparisons with other techniques. The new ChEVAR findings show favourable mid- and long-term clinical outcomes, even in elective patients. These results, comparable to those related to fenestrated endografts, have been achieved through standardisation in planning and materials. An adequate endograft oversizing associated to the right aortic neck length is fundamental to avoid ChEVAR-related complications, such as type 1a endoleaks. These data indicate that ChEVAR, compared to other complex endovascular treatments, has comparable outcomes along with features that could make it an essential option in every clinical settin

Acoustic Emission from crumpling paper

From magnetic systems to the crust of the earth, many physical systems that exibit a multiplicty of metastable states emit pulses with a broad power law distribution in energy. Digital audio recordings reveal that paper being crumpled, a system that can be easily held in hand, is such a system. Crumpling paper both using the traditional hand method and a novel cylindrical geometry uncovered a power law distribution of pulse energies spanning at least two decades: (exponent 1.3 - 1.6) Crumpling initally flat sheets into a compact ball (strong crumpling), we found little or no evidence that the energy distribution varied systematically over time or the size of the sheet. When we applied repetitive small deformations (weak crumpling) to sheets which had been previously folded along a regular grid, we found no systematic dependence on the grid spacing. Our results suggest that the pulse energy depends only weakly on the size of the paper regions responsible for sound production.Comment: 12 pages of text, 9 figures, submitted to Phys. Rev. E, additional information availible at http://www.msc.cornell.edu/~houle/crumpling