Automatic Repair of Real Bugs: An Experience Report on the Defects4J Dataset

Defects4J is a large, peer-reviewed, structured dataset of real-world Java bugs. Each bug in Defects4J is provided with a test suite and at least one failing test case that triggers the bug. In this paper, we report on an experiment to explore the effectiveness of automatic repair on Defects4J. The result of our experiment shows that 47 bugs of the Defects4J dataset can be automatically repaired by state-of- the-art repair. This sets a baseline for future research on automatic repair for Java. We have manually analyzed 84 different patches to assess their real correctness. In total, 9 real Java bugs can be correctly fixed with test-suite based repair. This analysis shows that test-suite based repair suffers from under-specified bugs, for which trivial and incorrect patches still pass the test suite. With respect to practical applicability, it takes in average 14.8 minutes to find a patch. The experiment was done on a scientific grid, totaling 17.6 days of computation time. All their systems and experimental results are publicly available on Github in order to facilitate future research on automatic repair

Ducks, Geese, and Swans of the World: Tribe Tadornini (Sheldgeese and Shelducks)

Blue-winged Goose Andean Goose Magellan Goose Kelp Goose Ashy-headed Sheldgoose Ruddy-headed Sheldgoose Orinoco Goose Egyptian Goose Ruddy Shelduck Cape Shelduck Australian Shelduck New Zealand Shelduck Crested Shelduck Northern (Common) Shelduck Radjah Shelduck The most gooselike species of the subfamily Anatinae are the sheldgeese, which together with the closely related shelducks constitute the tribe Tadornini. This group of 14 species has a worldwide distribution except for North America. The typical sheldgeese are grazing birds, the ecological counterparts of the true geese, while the shelducks are mostly wading and dabbling birds, frequently feeding to a large extent on aquatic invertebrates. In all of the species the adult male has an enlarged bony bulla in the syrinx, which is evidently responsible for the whistling or whistlelike sounds that are important in sexual and aggressive displays. The females of all species have more reedy and typically gooselike or ducklike notes. In all species the males are larger than the females, and often differ appreciably from them in plumage. Although pair bonds are sometimes said to be permanent in the group, in some species at least they may be ruptured through interactions with outside males, and a premium is placed on male aggressiveness during sexual competition for mates. The wings are used in fighting and in most species they are strongly patterned, with white coverts and iridescent coloration on the secondaries or their greater coverts. The downy young are also typically patterned contrastingly in the shelducks and sheldgeese, a characteristic shared with various other cavity-nesting waterfowl

Shoulder muscle activation strategies differ when lifting or lowering a load

Purpose Lowering a load could be associated with abnormal shoulder and scapular motion. We tested the hypothesis that lowering a load involves different shoulder muscle coordination strategies compared to lifting a load. Methods EMG activity of 13 muscles was recorded in 30 healthy volunteers who lifted and lowered a 6, 12 or 18 kg box between three shelves. Kinematics, EMG levels and muscle synergies, extracted using non-negative matrix factorization, were analyzed. Results We found greater muscle activity level during lowering in four muscles (+ 1–2% MVC in anterior deltoid, biceps brachii, serratus anterior and pectoralis major). The movements were performed faster during lifting (18.2 vs. 15.9 cm/s) but with similar hand paths and segment kinematics. The number of synergies was the same in both tasks. Two synergies were identified in ~ 75% of subjects, and one synergy in the others. Synergy #1 mainly activated prime movers’ muscles, while synergy #2 co-activated several antagonist muscles. Synergies’ structure was similar between lifting and lowering (Pearson’s r ≈ 0.9 for synergy #1 and 0.7–08 for synergy #2). Synergy #2 was more activated during lowering and explained the greater activity observed in anterior deltoid, serratus anterior and pectoralis. Conclusion Lifting and lowering a load were associated with similar synergy structure. In 3/4 of subjects, lowering movements involved greater activation of a “multiple antagonists” synergy. The other subjects co-contracted all shoulder muscles as a unit in both conditions. These inter-individual differences should be investigated in the occurrence of shoulder musculoskeletal disorders

Développement d'indicateurs biomécaniques en manutention et leur application dans l'étude des différences entre les sexes lors de levers de charges en hauteur

Les blessures musculo-squelettiques du membre supérieur représentent un problème de santé publique dans le secteur de la manutention. En plus d’affecter la qualité de vie du travailleur, ces lésions entraînent une perte de temps de travail et une augmentation des coûts de production. Alors que nous avons des évidences épidémiologiques que les femmes manutentionnaires sont plus nombreuses que les hommes à souffrir de douleurs à l’épaule, la littérature fait défaut d’indices biomécaniques qui expliquent l'origine de cette différence. L'objectif général de cette thèse était d'améliorer l'évaluation des techniques de manutention du membre supérieur, avec trois objectifs spécifiques : (1) développer des indices cinématiques, électromyographiques et musculo-squelettiques synthétiques pour évaluer et différencier des techniques de manutention du membre supérieur ; (2) développer un logiciel libre d'analyse biomécanique ; et (3) utiliser les indices et le logiciel développés pour décrire les différences biomécaniques entre des femmes et des hommes manutentionnaires. Nous avons récolté des données de cinématique, d'électromyographie et de force sur 30 femmes et 30 hommes réalisant une tâche de manutention qui consistait à déplacer une boîte de 6 et 12 kg entre la hauteur des hanches et la hauteur des yeux. À partir de ces données, nous avons développé des indicateurs synthétiques : un indicateur cinématique utile pour identifier des techniques de manutention problématiques et plus généralement les fonctions articulaires ; des indicateurs électromyographiques qui permettent d'estimer la quantité d'activation musculaire et la co-contraction musculaire ; et des indicateurs musculo-squelettiques qui permettent d'estimer les contraintes musculaires totales et les contraintes appliquées à l'articulation glénohumérale. Nous avons implémenté ces indicateurs avec pyomeca, notre logiciel libre d'analyse biomécanique. Mis à disposition de la communauté biomécanique, pyomeca supporte des tâches utiles dans le quotidien d'un chercheur biomécanique, mais également des routines biomécaniques plus avancées, axées sur la mécanique du corps rigide et le traitement de signal. Ce dernier se démarque des logiciels biomécaniques existants parce que c'est une solution libre, conviviale, spécialisée et sûre. Nous avons ensuite appliqué les indices synthétiques pour décrire les différences biomécaniques entre les femmes et les hommes participant à notre expérimentation. L'indicateur cinématique a montré que les femmes employaient une technique de manutention moins sécuritaire, avec une plus grande contribution glénohumérale, une faible contribution des membres inférieurs et une boite plus éloignée du tronc. Ces différences de technique se sont répercutées sur les indicateurs électromyographiques et musculo-squelettiques, avec des activations musculaires deux fois plus importantes comparativement aux hommes et une moindre stabilité de l'articulation glénohumérale. Ces différences pourraient contribuer à expliquer la prévalence de blessure du membre supérieur plus élevée chez les femmes manutentionnaires. Cette thèse a donc permis de développer des indicateurs synthétiques et un logiciel libre d'analyse biomécanique qui pourraient permettre aux ergonomes d'évaluer l'exposition aux risques de blessures du membre supérieur pendant une tâche de travail dynamique. Appliqués à une population spécifique, ces indicateurs suggèrent qu'il est crucial d'accorder une attention particulière au sexe pendant l'évaluation d'une tâche de travail au-dessus des épaules.Work-related upper limb musculoskeletal disorders represent a public health challenge in the material handling industry. In addition to affecting the worker's quality of life, these injuries result in lost work time and increased production costs. While we have epidemiological evidence that more female material handlers suffer from shoulder pain than men, the literature is lacking biomechanical indicators that explain the origin of this difference. The general objective of this thesis was to improve the evaluation of upper limb handling techniques, with three specific objectives~: (1) to develop synthetic kinematic, electromyographic and musculoskeletal indicators to evaluate and differentiate upper limb handling techniques~; (2) to develop an open source biomechanical analysis software~; and (3) to use the developed indicators and software to describe the biomechanical differences between female and male workers. We collected kinematics, electromyography and force data on 30 women and 30 men performing a handling task that consisted in lifting a 6 and 12~kg box from hip to eye level. From these data, we developed synthetic indicators~: a kinematic indicator useful to identify poor handling techniques and more generally joint functions~; two electromyographic indicators to quantify the amount of muscle activation and muscle co-contraction~; and two musculoskeletal indicators to estimate total muscle stress and stress applied to the glenohumeral joint. We have implemented these indicators with pyomeca, our open-source biomechanical analysis software. Available to the biomechanical community, pyomeca provide basic operations useful in the daily workflow of a biomechanical researcher, but also more advanced biomechanical routines geared towards rigid body mechanics and signal processing. pyomeca stands from existing biomechanical software because it is an open-source, user-friendly, specialized and secure solution. We then applied our synthetic indicators to describe the biomechanical differences between the women and men participating in our experiment. The kinematic indicator showed that women used a poor handling technique, with a higher glenohumeral contribution, a low contribution from the lower limbs and a box further away from the trunk. These differences in technique affected the electromyographic and musculoskeletal indicators, with twice as much muscle activation compared to men and less glenohumeral stability. These results may contribute to the sex difference in the prevalence of upper limb musculoskeletal disorders. This thesis has enabled the development of biomechanical indicators and an open-source software that could allow ergonomists to assess the upper limb exposure during a dynamic lifting task. Applied to a specific population, these indicators argue for a careful consideration of sex during ergonomics intervention, particularly during overhead work

Shoulder electromyography-based indicators to assess manifestation of muscle fatigue during laboratory-simulated manual handling task

Muscle fatigue is a risk factor for developing shoulder musculoskeletal disorders. The aim of this study was to identify shoulder electromyographic indicators that are most indicative of muscle fatigue during a laboratory simulated manual handling task. Thirty-two participants were equipped with electromyographic electrodes on 10 shoulder muscles and moved boxes for 45-minutes. The modified rate of perceived exertion (mRPE) was assessed every 5-minutes and multivariate linear regressions were performed between myoelectric manifestation of fatigue (MMF) and the mRPE scores. During a manual handling task representative of industry working conditions, spectral entropy, median frequency, and mobility were the electromyographic indicators that explained the largest percentage of the mRPE. Overall, the deltoids, biceps and upper trapezius were the muscles that most often showed significant changes over time in their electromyographic indicators. The combination of these three indicators may improve the accuracy for the assessment of MMF during manual handling

Cylinder-to-cylinder high-pressure exhaust gas recirculation dispersion effect on opacity and NOx emissions in a diesel automotive engine

[EN] The objective of the study is to determine the effect of the high-pressure exhaust gas recirculation dispersion in automotive diesel engines in NOx and smoke emissions in steady engine operation. The investigation quantifies the NOx and smoke emissions as a function of the dispersion of the high-pressure exhaust gas recirculation among cylinders. The experiments are performed on a test bench with a 1.6-L automotive diesel engine. In order to track the high-pressure exhaust gas recirculation dispersion in the intake pipes, a valves system to measure CO2, that is, exhaust gas recirculation rate, was installed pipe to pipe. In addition, a valves device to measure NOx emissions cylinder to cylinder in the exhaust was installed. Moreover, a smoke meter device was installed downstream the turbine, to measure the effect of the high-pressure exhaust gas recirculation dispersion on smoke emissions. Five different engine speeds were studied with different torque levels; thus, the engine map was widely studied, from 1250 to 3000 r/min and between 6 and 20 bar of brake mean effective pressure. The exhaust gas recirculation rate varies between 4% and 25% depending on the operating point. The methodology focused on experimental tools combining traditional measuring devices with a specific valves system, which offers accurate information about species concentration in both the intake and the exhaust manifolds. The study was performed at constant raw NOx emissions to observe the effect of the exhaust gas recirculation dispersion in the opacity and fuel consumption. The study concludes that when the exhaust gas recirculation dispersion is low, the opacity presents reduced values in all operating points. However, above a certain level of exhaust gas recirculation dispersion, the opacity increases dramatically with different slopes depending on the engine running condition. This study allows quantifying the exhaust gas recirculation dispersion threshold. In addition, the exhaust gas recirculation dispersion could contribute to increase the fuel consumption up to 3.5%.Macian Martinez, V.; Luján, JM.; Climent, H.; Miguel-García, J.; Guilain, S.; Boubennec, R. (2021). Cylinder-to-cylinder high-pressure exhaust gas recirculation dispersion effect on opacity and NOx emissions in a diesel automotive engine. International Journal of Engine Research. 22(4):1154-1165. https://doi.org/10.1177/1468087419895401S1154116522

Outcomes of conservatively managed coracoid fractures in wild birds in the United Kingdom

Coracoid fractures are a frequent presentation in wild birds, commonly due to collisions with motor vehicles, windows, or other obstacles such as pylons. Despite this, there are few literature reports of outcomes, and those published consist of small numbers of animals, with conflicting results when comparing conservative management with surgical intervention. Outcomes of 232 adult wild birds in the United Kingdom (UK), surviving more than 48 hours after admission, with only closed unilateral coracoid fractures confirmed on radiography were retrospectively analysed. There was a high success rate for conservative management, with 75% (95% confidence interval of 69-80%, n=174/232) of all birds successfully released back to the wild. The proportion of raptors successfully returned to the wild was even higher at 97% (95% CI 85-99%, n=34/35). A statistically significant difference of 26% (95% CI of 18-34%, Fishers exact test p<0.001, Z=6.08) was demonstrated, when comparing the raptor outcomes (97% success, n=34/35) to the non-raptor outcomes (71%, n=140/198). The median time in captive care until released back to the wild was 30 days (95% CI 27-33 days). Conservative management of coracoid fractures in wild birds in the UK, and in particular in raptors, appears to result in good outcomes. The approach is low cost and non-invasive, in contrast to surgery, and is recommended as the first line approach of choice in these cases

When App Stores Listen to the Crowd to Fight Bugs in the Wild

update for oadoi on Nov 02 2018International audienceApp stores are digital distribution platforms that put available apps that run on mobile devices. Current stores are software repositories that deliver apps upon user requests. However, when an app has a bug, the store continues delivering defective apps until the developer uploads a fixed version. Thus, impacting on the reputation of both store and app developer. In this paper, we envision a new generation of app stores that: (a) reduce human intervention to maintain mobile apps; and (b) enhance store services with smart and autonomous functionalities to automatically increase the quality of the delivered apps. We sketch a prototype of our envisioned app store and we discuss the functionalities that current stores can enhance by incorporating automatic software repair techniques