1,610 research outputs found

    Open Source, Agile and Reliability Measures

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    As open source and agile development do work in some circumstances, particularly with regard to shorter and more frequent release policy, we wonder whether the defect profile (reliability growth) found in the open-source projects so far is typical of open-source software development or of software developed iteratively and incrementally. To investigate this, we examined an open source web testing tool developed by an agile leading company. The results of this analysis indicate two findings. First, it supports the tentative findings that iteratively developed software does not exhibit a standard reliability growth in the defect modeling, and second, somewhat surprisingly that the defect density is reducing, as a sign of improving in quality yet the normal measure of software reliability are not useful

    Reliability growth of open source software using defect analysis

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    We examine two active and popular open source products to observe whether or not open source software has a different defect arrival rate than software developed in-house. The evaluation used two common models of reliability growth models; concave and S-shaped and this analysis shows that open source has a different profile of defect arrival. Further investigation indicated that low level design instability is a possible explanation of the different defect growth profile. © 2008 IEEE

    A comparison of the reliability growth of open source and in-House software

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    As commercial developers have established processes to assure software quality, open source software depends largely on community usage and defect reporting to achieve some level of quality. Thus, quality of open source software may vary. We examined defects reported in two active and popular open source software projects and an in-house project. The results of this analysis indicate that the reliability growth of each is quite distinct and that the defect profile of open source software appears to be a consequence of the open source software development method itself. © 2008 IEEE

    Test adequacy assessment using test-defect coverage analytic model

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    Software testing is an essential activity in software development process that has been widely used as a means of achieving software reliability and quality. The emergence of incremental development in its various forms required a different approach to determining the readiness of the software for release. This approach needs to determine how reliable the software is likely to be based on planned tests, not defect growth and decline as typically shown in reliability growth models. A combination of information from a number of sources into an easily understood dashboard is expected to provide both qualitative and quantitative analyses of test and defect coverage properties. Hence, Test-Defect Coverage Analytic Model (TDCAM) is proposed which combines test and defect coverage information presented in a dashboard to help deciding whether there are enough tests planned. A case study has been conducted to demonstrate the usage of the proposed model. The visual representations and results gained from the case study show the benefits of TDCAM in assisting practitioners making informed test adequacy-related decisions

    Effect of Temperature and Heat Treatment on Crack Growth Acoustic Emission in 7075 Aluminum

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    The acoustic emission activity due to crack advance in 7075 aluminum alloys has been found to vary with both temperature and heat treatment. An Increase in temperature or overaging of material in the -T6 condition each reduces the acoustic emission activity by changing the probability of occurrence of acoustic emission events and lowering their amplitudes. These observations suggest that the acoustic emission source mechanism is not inclusion fracture but rather is a property of the ductile matrix

    Visual arguments in film

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    Nuestro objetivo es señalar algunas diferencias entre los argumentos verbales y visuales, y promover la perspectiva retórica de la argumentación, yendo más allá de la relevancia de la lógica y de la pragmática. En nuestra opinión, si ha de ser racional y aceptable como argumentación (visual), un film debe dirigirse a espectadores que tienen creencias informadas sobre el tema visto en la pantalla y sobre las limitaciones y las convenciones del medio. En nuestras reflexiones, aplicamos el análisis retórico al cine como un acto simbólico, humano y comunicativo que a veces puede entenderse como un argumento trazado visualmente. Como mezcla de estímulos visuales, auditivos y verbales, el film exige una interpretación y una (re)construcción activas y complejas. Nuestra sugerencia es concentrarse en cinco elementos diferentes, pero relacionados entre sí. La reconstrucción y la evaluación del argumento visual se basarán en esos elementos, y todo el proceso constituirá una argumentación visual.Our aim is to point out some differences between verbal and visual arguments, promoting the rhetorical perspective of argumentation beyond the relevance of logic and pragmatics. In our view, if it is to be rational and successful, film as (visual) argumentation must be addressed to spectators who hold informed beliefs about the theme watched on the screen and the medium’s constraints and conventions. In our reflections to follow, we apply rhetorical analysis to film as a symbolic, human, and communicative act that may sometimes be understood as a visually laid out argument. As a mixture of visual, auditory, and verbal stimuli, film demands active and complex interpretation and (re)construction. Our suggestion is to focus on five different but interrelated elements. The reconstruction and evaluation of the visual argument will be based on those elements, and the whole process will be one of visual argumentation

    A pulsed-power implementation of “Laser Gate” for increasing laser energy coupling and fusion yield in magnetized liner inertial fusion (MagLIF)

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    Magnetized Liner Inertial Fusion (MagLIF) at Sandia National Laboratories involves a laser preheating stage where a few-ns laser pulse passes through a few-micron-thick plastic window to preheat gaseous fusion fuel contained within the MagLIF target. Interactions with this window reduce heating efficiency and mix window and target materials into the fuel. A recently proposed idea called “Laser Gate” involves removing the window well before the preheating laser is applied. In this article, we present experimental proof-of-principle results for a pulsed-power implementation of Laser Gate, where a thin current-carrying wire weakens the perimeter of the window, allowing the fuel pressure to push the window open and away from the preheating laser path. For this effort, transparent targets were fabricated and a test facility capable of studying this version of Laser Gate was developed. A 12-frame bright-field laser schlieren/shadowgraphy imaging system captured the window opening dynamics on microsecond timescales. The images reveal that the window remains largely intact as it opens and detaches from the target. A column of escaping pressurized gas appears to prevent the detached window from inadvertently moving into the preheating laser path

    The Minimum Information Required for a Glycomics Experiment (MIRAGE) project: improving the standards for reporting glycan microarray-based data

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    MIRAGE (Minimum Information Required for A Glycomics Experiment) is an initiative that was created by experts in the fields of glycobiology, glycoanalytics, and glycoinformatics to produce guidelines for reporting results from the diverse types of experiments and analyses used in structural and functional studies of glycans in the scientific literature. As a sequel to the guidelines for sample preparation (Struwe et al. 2016, Glycobiology, 26, 907-910) and mass spectrometry (MS) data (Kolarich et al. 2013, Mol. Cell Proteomics. 12, 991-995), here we present the first version of guidelines intended to improve the standards for reporting data from glycan microarray analyses. For each of eight areas in the workflow of a glycan microarray experiment, we provide guidelines for the minimal information that should be provided in reporting results. We hope that the MIRAGE glycan microarray guidelines proposed here will gain broad acceptance by the community, and will facilitate interpretation and reproducibility of the glycan microarray results with implications in comparison of data from different laboratories and eventual deposition of glycan microarray data in international databases

    Usability of a barcode scanning system as a means of data entry on a PDA for self-report health outcome questionnaires: a pilot study in individuals over 60 years of age

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    BACKGROUND: Throughout the medical and paramedical professions, self-report health status questionnaires are used to gather patient-reported outcome measures. The objective of this pilot study was to evaluate in individuals over 60 years of age the usability of a PDA-based barcode scanning system with a text-to-speech synthesizer to collect data electronically from self-report health outcome questionnaires. METHODS: Usability of the system was tested on a sample of 24 community-living older adults (7 men, 17 women) ranging in age from 63 to 93 years. After receiving a brief demonstration on the use of the barcode scanner, participants were randomly assigned to complete two sets of 16 questions using the bar code wand scanner for one set and a pen for the other. Usability was assessed using directed interviews with a usability questionnaire and performance-based metrics (task times, errors, sources of errors). RESULTS: Overall, participants found barcode scanning easy to learn, easy to use, and pleasant. Participants were marginally faster in completing the 16 survey questions when using pen entry (20/24 participants). The mean response time with the barcode scanner was 31 seconds longer than traditional pen entry for a subset of 16 questions (p = 0.001). The responsiveness of the scanning system, expressed as first scan success rate, was less than perfect, with approximately one-third of first scans requiring a rescan to successfully capture the data entry. The responsiveness of the system can be explained by a combination of factors such as the location of the scanning errors, the type of barcode used as an answer field in the paper version, and the optical characteristics of the barcode scanner. CONCLUSION: The results presented in this study offer insights regarding the feasibility, usability and effectiveness of using a barcode scanner with older adults as an electronic data entry method on a PDA. While participants in this study found their experience with the barcode scanning system enjoyable and learned to become proficient in its use, the responsiveness of the system constitutes a barrier to wide-scale use of such a system. Optimizing the graphical presentation of the information on paper should significantly increase the system's responsiveness

    Polymerase II Promoter Strength Determines Efficacy of microRNA Adapted shRNAs

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    Since the discovery of RNAi and microRNAs more than 10 years ago, much research has focused on the development of systems that usurp microRNA pathways to downregulate gene expression in mammalian cells. One of these systems makes use of endogenous microRNA pri-cursors that are expressed from polymerase II promoters where the mature microRNA sequence is replaced by gene specific duplexes that guide RNAi (shRNA-miRs). Although shRNA-miRs are effective in directing target mRNA knockdown and hence reducing protein expression in many cell types, variability of RNAi efficacy in cell lines has been an issue. Here we show that the choice of the polymerase II promoter used to drive shRNA expression is of critical importance to allow effective mRNA target knockdown. We tested the abundance of shRNA-miRs expressed from five different polymerase II promoters in 6 human cell lines and measured their ability to drive target knockdown. We observed a clear positive correlation between promoter strength, siRNA expression levels, and protein target knockdown. Differences in RNAi from the shRNA-miRs expressed from the various promoters were particularly pronounced in immune cells. Our findings have direct implications for the design of shRNA-directed RNAi experiments and the preferred RNAi system to use for each cell type
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