302 research outputs found
A Critical Review of "Automatic Patch Generation Learned from Human-Written Patches": Essay on the Problem Statement and the Evaluation of Automatic Software Repair
At ICSE'2013, there was the first session ever dedicated to automatic program
repair. In this session, Kim et al. presented PAR, a novel template-based
approach for fixing Java bugs. We strongly disagree with key points of this
paper. Our critical review has two goals. First, we aim at explaining why we
disagree with Kim and colleagues and why the reasons behind this disagreement
are important for research on automatic software repair in general. Second, we
aim at contributing to the field with a clarification of the essential ideas
behind automatic software repair. In particular we discuss the main evaluation
criteria of automatic software repair: understandability, correctness and
completeness. We show that depending on how one sets up the repair scenario,
the evaluation goals may be contradictory. Eventually, we discuss the nature of
fix acceptability and its relation to the notion of software correctness.Comment: ICSE 2014, India (2014
Forecasting severe ice storms using numerical weather prediction: the March 2010 Newfoundland event
The northeast coast of North America is frequently hit by severe ice storms. These freezing rain events can produce large ice accretions that damage structures, frequently power transmission and distribution infrastructure. For this reason, it is highly desirable to model and forecast such icing events, so that the consequent damages can be prevented or mitigated. The case study presented in this paper focuses on the March 2010 ice storm event that took place in eastern Newfoundland. We apply a combination of a numerical weather prediction model and an ice accretion algorithm to simulate a forecast of this event. <br><br> The main goals of this study are to compare the simulated meteorological variables to observations, and to assess the ability of the model to accurately predict the ice accretion load for different forecast horizons. The duration and timing of the freezing rain event that occurred between the night of 4 March and the morning of 6 March was simulated well in all model runs. The total precipitation amounts in the model, however, differed by up to a factor of two from the observations. The accuracy of the model air temperature strongly depended on the forecast horizon, but it was acceptable for all simulation runs. The simulated accretion loads were also compared to the design values for power delivery structures in the region. The results indicated that the simulated values exceeded design criteria in the areas of reported damage and power outages
Covrig: a framework for the analysis of code, test, and coverage evolution in real software
Copyright 2014 ACM.Software repositories provide rich information about the construction and evolution of software systems. While static data that can be mined directly from version control systems has been extensively studied, dynamic metrics concerning the execution of the software have received much less attention, due to the inherent difficulty of running and monitoring a large number of software versions. In this paper, we present Covrig, a flexible infrastructure that can be used to run each version of a system in isolation and collect static and dynamic software metrics, using a lightweight virtual machine environment that can be deployed on a cluster of local or cloud machines. We use Covrig to conduct an empirical study examining how code and tests co-evolve in six popular open-source systems. We report the main characteristics of software patches, analyse the evolution of program and patch coverage, assess the impact of nondeterminism on the execution of test suites, and investigate whether the coverage of code containing bugs and bug fixes is higher than average
Making data-driven porting decisions with Tuscan
Software typically outlives the platform that it was originally written for. To smooth the transition to new tools and platforms, programs should depend on the underlying platform as little as possible. In practice, however, software build processes are highly sensitive to their build platform, notably the implementation of the compiler and standard library. This makes it difficult to port existing, mature software to emerging platforms-web based runtimes like WebAssembly, resource-constrained environments for Internet-of-Things devices, or innovative new operating systems like Fuchsia. We present Tuscan, a framework for conducting automatic, deterministic, reproducible tests on build systems. Tuscan is the first framework to solve the problem of reproducibly testing builds cross-platform at massive scale.We also wrote a build wrapper, Red, which hijacks builds to tolerate common failures that arise from platform dependence, allowing the test harness to discover errors later in the build. Authors of innovative platforms can use Tuscan and Red to test the extent of unportability in the software ecosystem, and to quantify the effort necessary to port legacy software. We evaluated Tuscan by building an operating system distribution, consisting of 2,699 Red-wrapped programs, on four platforms, yielding a 'catalog' of the most common portability errors. This catalog informs data-driven porting decisions and motivates changes to programs, build systems, and language standards; systematically quantifies problems that platform writers have hitherto discovered only on an ad-hoc basis; and forms the basis for a common substrate of portability fixes that developers can apply to their software
New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"
Physics beyond the Standard Model predicts the possible existence of new
particles that can be searched at the low energy frontier in the sub-eV range.
The OSQAR photon regeneration experiment looks for "Light Shining through a
Wall" from the quantum oscillation of optical photons into "Weakly Interacting
Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T
transverse magnetic field over the unprecedented length of m.
In 2014, this experiment has been run with an outstanding sensitivity, using an
18.5 W continuous wave laser emitting in the green at the single wavelength of
532 nm. No regenerated photons have been detected after the wall, pushing the
limits for the existence of axions and ALPs down to an unprecedented level for
such a type of laboratory experiment. The di-photon couplings of possible
pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit
to be less than GeV and
GeV, respectively, at 95% Confidence Level.Comment: 6 pages, 6 figure
Bony canal and grooves of the middle meningeal artery: mythic structures in anatomy and neurosurgery?
Background: It has been previously published that the frontal branch of the middle meningeal artery (MMA) is usually embedded in a bony canal (BC). Although the incidence of the BC was over 70%, this structure is currently omitted both in anatomical nomenclature and in most of the literature. We found the same gap pertaining to the grooves for the MMA on the skull base. The aims of our study were to assess the incidence and morphometry of the MMA BC and grooves on the skull base.
Materials and methods: Computed tomography (CT) scans of 378 patients, 172 skull bases as well as 120 sphenoidal bones and 168 temporal bones, and 12 histological specimens from 3 men and 3 women and 3 different regions of the MMA course were assessed.
Results: Based on CT scans, the incidence of the BC was 85.44% and was significantly higher in females than in males. Most of the canals and grooves were bilateral. The mean canal length was 17.67 mm, the mean transverse diameter 1.33 mm, and the mean distance from the superior orbital fissure (dFOS) was 26.7 mm. In the skull bases, the BC incidence was 70.07%, the mean canal length 10.74 mm, and the mean dFOS was 19.16 mm. The groove for the MMA on the temporal and sphenoidal bones was present in 99.42% and 95.35%, respectively. Histological specimens confirmed the presence of the MMA and accompanying vein/s.
Conclusions: Based on our results, we suggest the addition of the BC and grooves for the middle meningeal vessels to the upcoming version of the Terminologia Anatomica
Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives
Recent theoretical and experimental studies highlight the possibility of new
fundamental particle physics beyond the Standard Model that can be probed by
sub-eV energy experiments. The OSQAR photon regeneration experiment looks for
"Light Shining through a Wall" (LSW) from the quantum oscillation of optical
photons into "Weakly Interacting Sub-eV Particles" (WISPs), like axion or
axion-like particles (ALPs), in a 9 T transverse magnetic field over the
unprecedented length of m. No excess of events has been
detected over the background. The di-photon couplings of possible new light
scalar and pseudo-scalar particles can be constrained in the massless limit to
be less than GeV. These results are very close to the
most stringent laboratory constraints obtained for the coupling of ALPs to two
photons. Plans for further improving the sensitivity of the OSQAR experiment
are presented.Comment: 7 pages, 7 figure
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