1,721,204 research outputs found
A comparison framework for runtime monitoring approaches
Get PDFThe full behavior of complex software systems often only emerges during operation. They thus need to be monitored at run time to check that they adhere to their requirements. Diverse runtime monitoring approaches have been developed in various domains and for different purposes. Their sheer number and heterogeneity, however, make it hard to find the right approach for a specific application or purpose. The aim of our research therefore was to develop a comparison framework for runtime monitoring approaches. Our framework is based on an analysis of the literature and existing taxonomies for monitoring languages and patterns. We use examples from existing monitoring approaches to explain the framework. We demonstrate its usefulness by applying it to 32 existing approaches and by comparing 3 selected approaches in the light of different monitoring scenarios. We also discuss perspectives for researchers
Profiling-based task scheduling for factory-worker applications in Infrastructure-as-a-Service clouds
Get PDFWith the recent advances of cloud computing, effective resource usage (e.g., CPU, memory or network) becomes an important question as application developers have to continuously pay for rented resources, even if they are not used effectively. In order to maintain required performance levels, it is currently common to reserve resources for peak resource usage or possible resource usage overlaps, if more than one task is executed on a host. While this is a reasonable approach for long-running applications or web servers, for some applications with disperse resource usage over time, this strategy causes significant over-provisioning and thus resource wastage and financial loss. In this paper we present a profiling-based task scheduling approach for factory-worker applications that schedules tasks within the defined resource limitations (e.g., existing machine memory size or network quota) and distributes the tasks in the cloud environment in order to use resources effectively. The evaluation of our approach approved the efficiency of the proposed algorithm and minimal performance overhead. In case of evaluated application, presented scheduling process leads up to 33% resource saving with only 1% of performance loss
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Výkon softwaru jako faktor při agilních metodách vývoje
No full textZa agilní metody vývoje softwaru jsou obecně považovány přístupy, kdy jsou programy často sestavovány, testovány a nasazovány. Výsledkem je tak kratší vývojový cyklus. Přístupy typu DevOps pak dovádí tuto koncepci do extrému, kdy jsou setřeny rozdíly mezi vývojovým a produkčním prostředím a nasazený software průběžně aktualizují. V tomto kontextu se tato práce zaměřuje na nalezení míst, kde by jednotliví účastníci měli mít větší povědomí o výkonu vyvíjeného softwaru. Práce nabízí přístupy a nástroje jak toto povědomí zvýšit; hlavním cílem je vytvářet lepší (rychlejší) software v kratším čase. Zlepšení je dosaženo pomocí testování, dokumentace a sledování výkonu během všech fází vývoje software. V této práci ukážeme (1) nástroje pro psaní testů výkonu pro jednotlivé komponenty (např. knihovny). Tyto testy zachycují a kodifikují předpoklady o výkonu a převádí je do spustitelných entit, které zjednodušují automatizaci a opakovatelnost. Pro vyhodnocení testů výkonu jsme (2) navrhli nové metody které dokáží automaticky nalézt regrese. Tyto metody jsou navrženy tak, aby braly v úvahu variabilitu dat pocházejících z měření výkonu softwaru a dokázaly odlišit skutečné regrese od šumu. Testy výkonnosti pak také (3) zužitkujeme pro vytvoření aktuální a přesné API dokumentace výkonu, která vývojářům usnadní psaní...Broadly, agile software development is an approach where code is frequently built, tested and shipped, leading to short release cycles. Extreme version is the DevOps approach where the development, testing and deployment pipelines are merged and software is continuously tested and updated. In this context our work focuses on identifying spots where the participants should be more aware of the performance and offers approaches and tools to improve their awareness with the ultimate goal of producing better software in shorter time. In general, the awareness is raised by testing, documenting, and monitoring the performance in all phases of the development cycle. In this thesis we (1) show a framework for writing performance tests for individual components (e.g. libraries). The tests capture and codify assumptions about the performance into runnable artifacts that simplify repeatability and automation. For evaluation of the performance tests we (2) propose new methods, which can automatically detect performance regressions. These methods are designed with inherent variation of performance data in mind and are able to filter it out in order to detect true regressions. Then we (3) reuse the performance tests to provide the developers with accurate and up-to-date performance API documentation that steer them...Katedra distribuovaných a spolehlivých systémůDepartment of Distributed and Dependable SystemsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult
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