Automatic bug triaging techniques using machine learning and stack traces

When a software system crashes, users have the option to report the crash using automated bug tracking systems. These tools capture software crash and failure data (e.g., stack traces, memory dumps, etc.) from end-users. These data are sent in the form of bug (crash) reports to the software development teams to uncover the causes of the crash and provide adequate fixes. The reports are first assessed (usually in a semi-automatic way) by a group of software analysts, known as triagers. Triagers assign priority to the bugs and redirect them to the software development teams in order to provide fixes. The triaging process, however, is usually very challenging. The problem is that many of these reports are caused by similar faults. Studies have shown that one way to improve the bug triaging process is to detect automatically duplicate (or similar) reports. This way, triagers would not need to spend time on reports caused by faults that have already been handled. Another issue is related to the prioritization of bug reports. Triagers often rely on the information provided by the customers (the report submitters) to prioritize bug reports. However, this task can be quite tedious and requires tool support. Next, triagers route the bug report to the responsible development team based on the subsystem, which caused the crash. Since having knowledge of all the subsystems of an ever-evolving industrial system is impractical, having a tool to automatically identify defective subsystems can significantly reduce the manual bug triaging effort. The main goal of this research is to investigate techniques and tools to help triagers process bug reports. We start by studying the effect of the presence of stack traces in analyzing bug reports. Next, we present a framework to help triagers in each step of the bug triaging process. We propose a new and scalable method to automatically detect duplicate bug reports using stack traces and bug report categorical features. We then propose a novel approach for predicting bug severity using stack traces and categorical features, and finally, we discuss a new method for predicting faulty product and component fields of bug reports. We evaluate the effectiveness of our techniques using bug reports from two large open-source systems. Our results show that stack traces and machine learning methods can be used to automate the bug triaging process, and hence increase the productivity of bug triagers, while reducing costs and efforts associated with manual triaging of bug reports

“Frances Burney's Legacy Duty Account” (1840)

In the twelfth and final volume of The Journals and Letters of Fanny Burney, Joyce Hemlow published, for the first time, a transcription of the will of Frances Burney d’Arblay (1752–1840), dated 6 March 1839 and proved on 17 February 1840, six weeks after her death.1 The will provides much valuable information on Burney’s final intentions for the disposal of her effects, including her vast horde of manuscripts, as well as on the state of her finances. Unknown to Hemlow or to subsequent scholars, however, another key document in the National Archives throws new light on these matters: “Burney’s Legacy Duty Account,” dated 19 October 1840, thanks to which we now have complete information about her finances at the time of her death.2 Of particular interest are its valuations of Burney’s literary manuscripts and correspondence, as well those of her father, the music historian and man of letters Dr. Charles Burney (1726–1814). As well as transcribing the “Legacy Duty Account” below, we shall consider why the Burneys received valuations for their manuscripts that are not only shockingly low from a modern perspective, but also significantly lower than those of several of their literary contemporaries

Contribution à l'étude quantique du carbure de tungstène neutre (WC) et ionisé (WCq+, q=1, 2)

Metal carbides and oxides are more interesting in catalytic and industrial domains. Tungsten carbide WC has been detected as serious substituent of platinum Pt catalytic. The ultimate goal of this thesis is theoretical studies of electronic structure, stability and the bound nature on WC, WO and its cations. Our preliminary research were motiving by the available spectroscopic data on W, W+, W2+, WC et WC2+. We used the methodology (CASSCF/MRCI/MRCI+Q/aug-cc-pV5Z(-PP)) implemented on MOLPRO package to perform quantum calculations with high accuracy taking into account the correlation and relativistic effects with a specific treatment of spin orbit coupling for some low lying excited electronic states of WCn+, (n=0, 1 et 2). Our results are shown in good agreement with those available in the literature. Furthermore, in this work for the first time we demonstrated that a carbide dication (WC2+) is thermodynamically stableLes carbures et oxydes des métaux de transition sont d'une importance capitale dans le domaine industriel voir catalytique. Le carbure de tungstène WC a été identifié comme un bon substituant des métaux nobles tel que le platine dans le domaine catalytique. Le but de ce travail de thèse est d'appliquer des méthodes de chimie quantique les plus poussées pour déterminer la structure électronique, la stabilité et la nature de liaison chimique des diatomiques WC et WC2+. Notre recherche préliminaire est motivée par les données spectroscopiques disponibles sur W, W+, W2+, WC et WC2+. La méthodologie adoptée, CASSCF/MRCI/MRCI+Q/aug-cc-pV5Z(-PP) implémentée dans le code MOLPRO, consiste à réaliser des calculs quantique tenant en compte des effets de corrélation et relativistes avec un traitement spécifique du couplage spin−orbite pour la recherche des courbes d'énergie potentielle de l'état fondamental et des états excités de plus basses énergies de WCn+ (n=0-2) tout en utilisant une base suffisamment étendue. Les résultats de ce travail sont en bon accord avec ceux disponibles dans la littérature. En outre, dans ce travail nous avons confirmé pour la première fois que le carbure diatomique dicationique WC2+ est thermodynamiquement stabl

L’américanité comme motif identitaire suivi du récit : Le gros éther

Ce mémoire en création littéraire porte sur le concept d’américanité et sur le sens qu’il peut prendre pour un écrivain d’aujourd’hui. Dans la partie théorique, je donne une vue d’ensemble de l’américanité, que je définis ici comme une posture ou un questionnement propre à celui qui tente de mettre en mots une réalité américaine. Elle concerne le rapport singulier au territoire, les idéaux culturels et les spécificités de la langue. Je m’intéresse aux thèmes, aux images et aux clichés qui lui sont propres, notamment l’errance, l’aliénation, le voyage et le passage à la vie adulte. Je fais aussi un recensement de quelques-uns des écrits les plus récents sur l’américanité, en relevant comment le terme a évolué. Je puise dans les écrits de chercheurs tels que René Lapierre, Jean Morency et Pierre-Paul Ferland. Ce faisant, je défends l’hypothèse que plus qu’une position politique ou socioculturelle, l’américanité est un sentiment qu’on porte en soi, une manière d’appréhender le réel. Le volet création de mon mémoire prend la forme d’un court roman (provisoirement intitulé Le gros éther) que je qualifie de noir rural et qui correspond, à mon avis, à une esthétique américaine. Il épouse les points de vue d’un père et de sa fille, qui ratissent la forêt et les routes à la recherche d’un ami porté disparu. Le rapport des personnages aux lieux y est central et sert de voie d’accès à la notion d’américanité

Renormalization group studies of quantum theories of gravity and matter

In this thesis, we study quantum theories of gravity and matter in the Renormalization Group approach. We observe light fermions in our universe which feature a remnant of chiral symmetry. While chiral symmetry appears to remain intact along the Renormalization Group flow of asymptotically safe approaches to quantum gravity, these computations are performed on a flat background. Mean field studies performed on negatively curved backgrounds however indicate chiral symmetry breaking in the form of gravitational catalysis. The study of the mean field RG flow on negatively curved spacetime leads to an upper bound for the ratio of curvature of local patches of spacetime to the RG scale. We extend these calculations to finite temperature and study how thermal fluctuations affect this bound from gravitational catalysis. Applying this thermal extension of the curvature bound to the asymptotic safety scenario of quantum gravity, it translates into an upper bound of numbers of fermion species allowed in our universe. Most approaches towards a UV complete quantum theory of gravity start with General Relativity as its classical theory. Einstein’s formulation of gravity can be summarized as pseudo-Riemannian geometry on a manifold equipped with a metric and a connection. While this connection is restricted to the Levi-Cevita connection in Einstein gravity and therefore is fully determined by the metric, there is a priori no fundamental reason to not use a general connection. This formalism, in which the metric and the general connection are treated as independent degrees of freedom, is referred to as Hilbert-Palatini gravity. In this thesis, we compute the most general solution to the connection for the Einstein-Hilbert-Palatini action and use it in an on-shell reduction scheme to compute the RG flow for the subsequent order in the truncation. We find a UV- attractive fixed point similar to the Reuter fixed point in quantum Einstein gravity

Desarrollo del planeamiento bibliotecario en America Latina

The librarian planning in the Latin American and its relation to the educational and others services. The periods 1950/59, 1963/67, 1968 up to day. It is discussed the literature about the planning theory and methodology in the hispan-american countries.Análise da idéia do planejamento bibliotecário na América Latina e sua inter-relação com o planejamento de serviços educacionais e outros. Revê os projetos e realizações no campo, a partir de seus antecedentes (1950 a 1959), e à luz de reuniões profissionais, congressos, seminários, jornadas, etc. e de suas recomendações. O período de 1963/67 é o início da preparação concreta de projetos. O período a partir de 1968 é fecundo em estudos e tentativas. O planejamento bibliotecário continua sendo tema constante de reuniões de profissionais. Estuda-se a literatura sobre a teoria e metodologia do planejamento nos países hispano-americanos