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

Online diagnosis of supercapacitors using extended Kalman filter combined with PID corrector

Supercapacitors are electrical energy storage devices with a high specific power density, a long cycle life and a good efficiency, which make them attractive alternative storage devices for various applications. However, supercapacitors are subject to a progressive degradation of their perfor-mance because of aging phenomenon. Therefore, it is very important to be able to estimate their State-of-Health during operation. Electrochemical Impedance Spectroscopy (EIS) is a very recog-nized technique to determine supercapacitors’ state-of-health. However, it requires the interrup-tion of system operation and thus cannot be performed in real time (online). In this paper, a new online identification method is proposed based on extended Kalman observer combined with a complementary PID corrector. The proposed method allows to accurately estimating supercapacitor resistance and capacitance, which are the main indicators of supercapacitor state-of-health. The new online identification method was applied for two voltage/current profiles using two different supercapacitors. The resistance/capacitance estimated by the new method and the conventional EKF were compared with those obtained by an experimental offline method. In comparison with conventional EKF, the capacitance obtained by the new method is significantly more accurate

“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

Optimized-Based Routing Protocols for Improving the Performance of Wireless Sensor Networks

新潟大学博士（工学）学位の種類: 博士（工学）. 報告番号: 乙第2210号. 学位記番号: 新大博（工）乙第50号. 学位授与年月日: 平成29年3月23日新大博（工）乙第50号thesi

Sabrosa Comida Salvadoreña

https://www.exhibit.xavier.edu/latino_reviews/1007/thumbnail.jp

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