Root cause prediction based on bug reports

This paper proposes a supervised machine learning approach for predicting the root cause of a given bug report. Knowing the root cause of a bug can help developers in the debugging process - either directly or indirectly by choosing proper tool support for the debugging task. We mined 54755 closed bug reports from the issue trackers of 103 GitHub projects and applied a set of heuristics to create a benchmark consisting of 10459 reports. A subset was manually classified into three groups (semantic, memory, and concurrency) based on the bugs' root causes. Since the types of root cause are not equally distributed, a combination of keyword search and random selection was applied. Our data set for the machine learning approach consists of 369 bug reports (122 concurrency, 121 memory, and 126 semantic bugs). The bug reports are used as input to a natural language processing algorithm. We evaluated the performance of several classifiers for predicting the root causes for the given bug reports. Linear Support Vector machines achieved the highest mean precision (0.74) and recall (0.72) scores. The created bug data set and classification are publicly available.Comment: 6 page

Combining Spreadsheet Smells for Improved Fault Prediction

Spreadsheets are commonly used in organizations as a programming tool for business-related calculations and decision making. Since faults in spreadsheets can have severe business impacts, a number of approaches from general software engineering have been applied to spreadsheets in recent years, among them the concept of code smells. Smells can in particular be used for the task of fault prediction. An analysis of existing spreadsheet smells, however, revealed that the predictive power of individual smells can be limited. In this work we therefore propose a machine learning based approach which combines the predictions of individual smells by using an AdaBoost ensemble classifier. Experiments on two public datasets containing real-world spreadsheet faults show significant improvements in terms of fault prediction accuracy.Comment: 4 pages, 1 figure, to be published in 40th International Conference on Software Engineering: New Ideas and Emerging Results Trac

Argumentationssequenzen in Konfliktgesprächen zwischen Müttern und Töchtern

Dieser Beitrag versucht, statistische Regelmäßigkeiten in der Abfolge von Sprecheinheiten Innerhalb von Gesprächen zu ermitteln. Das Augenmerk richtet sich auf die Unterscheidung und Erfassung von argumentativen Kategorien in Konfliktgesprächen zwischen Müttern und ihren jugendlichen Töchtern. Als konfliktäres Argument wird die Begründung einer Person in einer Konfliktsituation bezeichnet, mit der ein Ziel oder ein anderes Argument gestützt oder geschwächt werden soll. Wir betrachten Fakten, Bewertungen, Konnexe, Normen und Präferenzen als Elemente einer Kognition "konfliktäres Argument". Ein Argument kann bezogen auf ein Ziel oder ein anderes Argument stärkenden (stützenden, zusätzlich stützenden), modifizierenden (relativierenden) oder schwächenden (einwendenden, gegenbehauptenden) Charakter tragen. Neben argumentativen Elementen im engeren Sinne werden auch gesprächssteuernde Kategorien betrachtet: Initiativen (Aufforderungen, Fragen) sowie Reaktiven (positive, negative Reaktionen auf Argumente oder Initiativen). Die Art und Qualität der aktivierten und vorgebrachten Argumente wird als abhängig betrachtet von den Motiven der beteiligten Partner. Bei Müttern werden Kontrollmotive, bei Töchtern vor allem Individuierungsmotive an-genommen. Es wird erwartet, daß sich diese Tendenzen in den Mikrosequenzen niederschlagen. Datenbasis sind 60 Gespräche zwischen 30 Müttern und Töchtern im Alter von 12 bis 24 Jahren. Jede Dyade diskutierte zwei aktuelle Konflikte nach freier Wahl. Die transkribierten Gespräche wurden nach dem Mannheimer Argumentations-Kategorien-System, das sich an den o.a. theoretischen Konstrukten orientiert, in Einheiten zerlegt und klassifiziert. Die Kategorien erwiesen sich als ausreichend objektiv und rellabel. Die Auswertungen erfolgten über log-lineare und lag-sequentielle Analysen. Bei den Ergebnissen konnten wir die Phänomene der Zustimmungs-Relativierungs-Sequenz und der Argument-Reihung als In-turn-Sequenzen Identifizieren. Als turn- übergreifende Muster fielen besonders deutlich auf der negative Reaktionszyklus: eine über drei bis vier lags andauernde Folge von negativen Reaktionen auf Argumente. Weiter bezeichneten wir mit Argumentkonfrontation die Tendenz, daß Gegenargumente überzufällig häufig mit Gegenargumenten gekontert wurden. Besonders bei Müttern waren weiter repetitive Phänomene erkennbar. Sie bestanden darin, daß Initiativen, Insbesondere Aufforderungen und Klärungsfragen nach einer Reaktion wiederholt wurden. Wir nennen das "Insistieren" bzw. "Nachhaken". Mit Bezug auf die Dimension der Argumentelemente konnten deutliche Sequenzen von Abfolgen nicht ermittelt werden. Die Partnerinnen neigten dazu, ihre Argumente jeweils auf der gleichen Ebene (Fakten, Bewertungen, Konnexen und Präferenzen) anzusiedeln, was als Hinweis auf kohärent elementbezogenes Argumentieren aufzufassen Ist. Die Ergebnisse bestätigen in großen Teilen die Erwartungen. Die verschiedenen Mikro-Gesetzmäßigkeiten werden unter Bezug auf die von Jones und Gérard (1967) nach der Kontingenz unterschiedenen Typen von Interaktionen interpretiert.In this paper, we focus on the Identification of systematic sequences of verbal units In dialogues. To this aim, we try to distinguish and assess categories of argumentation in the course of verbal conflicts between mothers and their adolescent daughters. Reasons given by a person In a conflict situation to support or weaken a goal or another argument are considered conflictuous arguments. As to cognitions called "conflictuous arguments“, we distinguish facts, evaluations, connexes, norms, and preferences as major elements. An argument may assume different functions with regard to goals or other arguments: supporting (support, additional support), modifying (qualification), weakening (objection, counter argument). Besides argumentative elements, we also consider categories of conversation management: Initiatives (request, question), reactives (positive or negative responses to arguments or Initiatives). The type and quality of arguments which are activated and put forward are seen as dependent on the motivations of the participants In the dialogue. We assume control as a major motivation among mothers, whereas daughters are assumend to rather show motivations of individuation. We expect these to be expressed in micro sequences of mother- daughter dialogues. Our empirical analyses are based on 60 dialogues recorded with 30 dyads of female adolescents who were between ages 12 and 24 and their mothers. Following the Identification of two real everyday conflicts as relevant for a given dyad, the mother and daughter consecutively discussed both issues. The dialogues were tape-recorded and transcribed for further analyses. Units of communication were determined and categorized using the Mannheim Argumentation Category System which closely follows the constructs introduced above. Reliability checks yielded satisfying results for all categories. The data were analyzed using hierarchical tests of log-linear models as well as log-sequential analyses. Agreement- qualification sequences, negative response cycles, i.e., sequences of negative responses to arguments encompassing up to four lags, were particularly salient. Moreover, we observed what we called argument confrontation: Counter-arguments are met by counter-arguments again more often than could be expected by chance. With mothers, in particular, further repetitive sequences could be Identified. A case In point are initiatives, namely requests and clarification questions, which mothers continued to put forward even after the daughter’s response. We have called this insisting. Our analyses focusing on the dimensions of argumentative elements did not provide unequivocal results. There is some evidence for the mothers’ and daughters’ tendency to respond to arguments employing argumentative elements of the same type (fact, evaluation, connex, preference) which may point to element-based coherence as an organizing feature of verbal conflicts. Summarizing, the data provided empirical support for most of our theoretical expectations. The findings concerning regularities of argumentation on the micro-level are discussed drawing upon Jones and Gerard’s (1967) distinction of different types of Interactions

Neural correlates of the perception of dynamic versus static facial expressions of emotion

Aim: This study investigated brain areas involved in the perception of dynamic facial expressions of emotion

Using LNT Formal Descriptions for Model-Based Diagnosis

International audienceProviding models for model-based diagnosis has always been a challenging task. There has never been an agreement on an underlying modeling language, making it almost impossible to share models within our community. In addition, there are other domains like formal methods or model-based testing relying on system models for formal verification and automated test case generation. Although, there we face the situation of different modeling languages as well, the question remains whether it is possible to re-use these models in the context of model-based diagnosis. In this paper , we elaborate on this question and show how models written in LNT can be used for fault local-ization only requiring simple modification. This allows re-using formal method's models for diagnosis directly. Besides discussing the underlying principles, we also present a use case showing the applicability of the methods

Die Beziehung zwischen Eltern und Jugendlichen und das Argumentieren in konfliktären Interaktionen

In Anlehnung an die Theorie der Individuation wird vermutet, daß das Gesprächsverhalten von Müttern und jugendlichen Töchtern in konfliktären Interaktionen durch Kontrolltendenzen auf seiten der Mütter und Individualisierungstendenzen auf seiten der Töchter determiniert wird. Als Datenbasis dienten 140 Konfliktgespräche zwischen 110 Müttern und ihren jugendlichen Töchtern. Die Ergebnisse stehen in Einklang mit den entwicklungspsychologischen Annahmen. (SH2

Validation of Aeolus wind products above the Atlantic Ocean

In August 2018, the first Doppler wind lidar in space called Atmospheric Laser Doppler Instrument (ALADIN) was launched on board the satellite Aeolus by the European Space Agency (ESA). Aeolus measures profiles of one horizontal wind component (i.e., mainly the west-east direction) in the troposphere and lower stratosphere on a global basis. Furthermore, profiles of aerosol and cloud properties can be retrieved via the high spectral resolution lidar (HSRL) technique. The Aeolus mission is supposed to improve the quality of weather forecasts and the understanding of atmospheric processes. We used the opportunity to perform a unique validation of the wind products of Aeolus by utilizing the RV Polarstern cruise PS116 from Bremerhaven to Cape Town in November/December 2018. Due to concerted course modifications, six direct intersections with the Aeolus ground track could be achieved in the Atlantic Ocean west of the African continent. For the validation of the Aeolus wind products, we launched additional radiosondes and used the EARLINET/ACTRIS lidar Polly XT for atmospheric scene analysis. The six analyzed cases prove that Aeolus is able to measure horizontal wind speeds in the nearly west-east direction. Good agreements with the radiosonde observations could be achieved for both Aeolus wind products-the winds observed in clean atmospheric regions called Rayleigh winds and the winds obtained in cloud layers called Mie winds (according to the responsible scattering regime). Systematic and statistical errors of the Rayleigh winds were less than 1.5 and 3.3ms-1, respectively, when compared to radiosonde values averaged to the vertical resolution of Aeolus. For the Mie winds, a systematic and random error of about 1ms-1 was obtained from the six comparisons in different climate zones. However, it is also shown that the coarse vertical resolution of 2km in the upper troposphere, which was set in this early mission phase 2 months after launch, led to an underestimation of the maximum wind speed in the jet stream regions. In summary, promising first results of the first wind lidar space mission are shown and prove the concept of Aeolus for global wind observations. © 2020 Author(s)

The vertical aerosol type distribution above Israel – 2 years of lidar observations at the coastal city of Haifa

For the first time, vertically resolved long-term lidar measurements of the aerosol distribution were conducted in Haifa, Israel. The measurements were performed by a PollyXT multi-wavelength Raman and polarization lidar. The lidar was measuring continuously over a 2-year period from March 2017 to May 2019. The resulting data set is a series of manually evaluated lidar optical property profiles. To identify the aerosol types in the observed layers, a novel aerosol typing method that was developed at TROPOS is used. This method applies optimal estimation to a combination of lidar-derived intensive aerosol properties to determine the statistically most-likely contribution per aerosol component in terms of relative volume. A case study that shows several elevated aerosol layers illustrates this method and shows, for example, that coarse dust particles are observed up to 5ĝ€¯km height over Israel. From the whole data set, the seasonal distribution of the observed aerosol components over Israel is derived. Throughout all seasons, coarse spherical particles like sea salt and hygroscopically grown continental aerosol were observed. These particles originate from continental Europe and were transported over the Mediterranean Sea. Sea-salt particles were observed frequently due to the coastal site of Haifa. The highest contributions of coarse spherical particles are present in summer, autumn, and winter. During spring, mostly coarse non-spherical particles that are attributed to desert dust were observed. This is consistent with the distinct dust season in spring in Israel. An automated time-height-resolved air mass source attribution method identifies the origin of the dust in the Sahara and the Arabian deserts. Fine-mode spherical particles contribute significantly to the observed aerosol mixture during all seasons. These particles originate mainly from the industrial region at the bay of Haifa

Critical and direct involvement of the CD23 stalk region in IgE binding

BackgroundThe low-affinity receptor for IgE, FcεRII (CD23), contributes to allergic inflammation through allergen presentation to T cells, regulation of IgE responses, and enhancement of transepithelial allergen migration.ObjectiveWe sought to investigate the interaction between CD23, chimeric monoclonal human IgE, and the corresponding birch pollen allergen Bet v 1 at a molecular level.MethodsWe expressed 4 CD23 variants. One variant comprised the full extracellular portion of CD23, including the stalk and head domain; 1 variant was identical with the first, except for an amino acid exchange in the stalk region abolishing the N-linked glycosylation site; and 2 variants represented the head domain, 1 complete and 1 truncated. The 4 CD23 variants were purified as monomeric and structurally folded proteins, as demonstrated by gel filtration and circular dichroism. By using a human IgE mAb, the corresponding allergen Bet v 1, and a panel of antibodies specific for peptides spanning the CD23 surface, both binding and inhibition assays and negative stain electron microscopy were performed.ResultsA hitherto unknown IgE-binding site was mapped on the stalk region of CD23, and the non–N-glycosylated monomeric version of CD23 was superior in IgE binding compared with glycosylated CD23. Furthermore, we demonstrated that a therapeutic anti-IgE antibody, omalizumab, which inhibits IgE binding to FcεRI, also inhibited IgE binding to CD23.ConclusionOur results provide a new model for the CD23-IgE interaction. We show that the stalk region of CD23 is crucially involved in IgE binding and that the interaction can be blocked by the therapeutic anti-IgE antibody omalizumab