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Erkennung von Adaptionskonflikten zur Laufzeit unter Benutzung von [email protected]
No full textSelbstadaptive Softwaresysteme sind in der Lage, sich an die Heterogenität heutiger Computersysteme anzupassen. Adaptionen ermöglichen eine korrekte Funktionsweise trotz unterschiedlicher Computerplattformen, Fähigkeiten, Konfigurationen und Kontextsituationen. Hierfür muss das Softwaresystem trotz der Änderungen durch Adaptionen immer korrekt funktionieren. Um dieses Ziel zu erreichen kann Verifikation zur Designzeit mit einer Analyse zur Laufzeit kombiniert werden. Eine Verifikation zur Designzeit ermöglicht die frühzeitige Erkennung und Beseitigung von Problemen. Allerdings ist der Zustandsraum, welcher durch Adaption erreicht werden kann, oft sehr groß oder, in einigen Fällen, zur Designzeit nicht vollständig bekannt. Dies macht eine komplette Verifikation zur Designzeit unpraktisch oder sogar unmöglich. Analyse zur Laufzeit hat den Vorteil, dass ein großer Teil der zur Designzeit noch unbekannten Variablen feststeht. Statt einer Analyse des gesamten Zustandsraumes kann die Laufzeitanalyse auf dem aktuellen Zustand basieren.
Das korrekte Verhalten der Adaptionen ist einer der Aspekte, die sichergestellt werden müssen. Adaptionen verursachen Änderungen im Softwaresystem. Diese Änderungen können miteinander in Konflikt stehen. Das laufende Softwaresystem muss diese Konflikte erkennen können, um auf sie zu reagieren. In dieser Doktorarbeit beschreiben wir den Trollmann Ansatz zur Erkennung von Adaptionskonflikten. Dieser Ansatz kann zwei Typen von Adaptionskonflikten erkennen: Adaption-Adaption Konflikte und Adaption-Konsistenz Konflikte. Adaption-Adaption Konflikte treten auf, wenn Adaptionen sich gegenseitig beeinflussen. Dies führt dazu, dass verschiedene Reihenfolgen der gleichen Adaptionen unterschiedliche Ergebnisse liefern. Es kann auch vorkommen, dass nach einer Adaption eine andere nicht mehr durchgeführt werden kann. Adaption-Konsistenz Konflikte sind Situationen, in denen die Adaptionen das System in einen inkonsistenten Zustand führen. Um Adaptionskonflikte zu lösen muss ein selbstadaptives Softwaresystem in der Lage sein, diese zu erkennen.
Modellgetriebene Softwareentwicklung kann verwendet werden, um die Komplexität der Entwicklung und Handhabung von Softwaresystemen zu reduzieren. Bei einigen Ansätzen bleiben die Modelle zur Laufzeit erhalten und werden mit dem laufenden Softwaresystem synchronisiert. Der Trollmann Ansatz basiert auf einem solchen Ansatz. Adaptionen und Konsistenzbedingungen können auf diesen Modellen beschrieben werden. Als Formale Basis definieren wir einen Formalismus, der in der Lage ist, mehrere Modelle und deren Relation zu repräsentieren. Dieser Formalismus kann mit Graph Transformation und mit Nested Conditions kombiniert werden, um Adaptionen und Konsistenzbedingungen zu beschreiben. Basierend auf dieser Kombination von Formalismen definieren wir eine Analysemethode für Adaptionskonflikte. Die Analyse ermöglicht die Erkennung beider Konfliktarten. Für erkannte Konflikte werden die beteiligten Adaptionen, Modellelemente und elementaren Adaptionsoperationen (Erstellen und Löschen von Modellelementen) extrahiert.
Das korrekte Verhalten des Trollmann Ansatzes wird durch Theoreme beschrieben und in der Arbeit bewiesen. Zusätzlich beschreiben wir die Implementierung des Trollmann Ansatzes im Rahmen des Eclipse Modeling Frameworks. Diese Implementierung wurde genutzt, um die Konflikterkennung im Rahmen eines Forschungsprojektes an der TU Berlin zu evaluieren.Self-adaptive software systems aim to cope with the heterogeneity of today’s computing environments by adjusting themselves. Adaptations enable the software system to function correctly despite different computing platforms, capabilities, configurations and context-of-use situations. Self-adaptive software systems need to assure correct behaviour despite the changes imposed by adaptations. To achieve this goal design time verification can be complemented with run time assurance. Design time verification enables the detection and resolution of problems at design time. However, due to its adaptations the state space of a self-adaptive software system is often very large or, in some cases, partially unknown at design. This makes a complete verification impractical or even impossible. Run time assurance methods profit from the fact that a lot of the variables that are free at design time are bound at run time. Instead of a verification of the complete state space such methods can concentrate on assuring that there are no failures in the current state of the software system.
One aspect that needs to be assured at run time is the correct behaviour of the adaptation itself. Adaptations denote changes in the software system that can be in conflict with each other. The running software system needs to be able to detect these conflicts to resolve them. In this thesis we present the Trollmann approach to adaptation conflict detection. This approach is able to detect two types of adaptation conflicts: adaptation-adaptation and adaptation-consistency conflicts. Adaptation-adaptation conflicts are situations in which adaptations impact each other, leading to different results when applied in different order. The application of one adaptation can even disable another adaptation. Adaptation-consistency conflicts are situations in which adaptations leave the software system in an inconsistent state. The running software system needs to be able to detect and resolve these conflicts.
Model driven engineering has been applied to tame the complexity of the development and management of software systems. The Trollmann approach assumes a model driven engineering approach in which the models are available at run time and reflect the current state of the software system, its adaptations and its consistency requirements. The detection of adaptation conflicts is based on these models. As formal foundation for the approach we define the formalism graph diagrams that can be used to represent multiple models and their relation. This formalism is combined with graph transformation and nested conditions to describe adaptations and consistency requirements. Based on this combination of formalisms we define analysis methods for adaptation conflicts. These analysis methods are able to detect both types of conflicts and to point out the adaptations, model elements and elementary adaptation actions (i.e., the creation and deletion of model elements) that are involved in the conflict. This information can be used by a conflict resolution mechanism.
The correct behaviour of the Trollmann approach is described by a set of theorems that are proven in this thesis. In addition, we present an implementation of the Trollmann approach in the scope of the Eclipse Modeling Framework. This implementation has been used to evaluate the performance of the analysis algorithms and test the approach in the scope of a research project at the TU Berlin
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
Towards synchronizing relations between artifacts in the Java technological space
Get PDFO uso de modelos em processos de engenharia de software tem crescido nos últimos anos. Ao passo que o uso cresce, cresce também a relevância de alguns problemas relacionados à área. Um deles é o problema de sincronização de modelos, que consiste basicamente em manter todos os modelos de uma aplicação de software consistentes entre si. Em outras palavras, os modelos de um software tendem a ser mudados ao longo do seu tempo de vida, e quando isto acontece, estas mudanças têm que ser devidamente despachadas a todos os modelos. Para aplicações de software de grande porte é inviável realizar tal procedimento de sincronização manualmente, portanto, é desejada a criação de métodos automáticos capazes de sincronizar os modelos do software. Não exploramos este problema para qualquer tipo de software, ao invés disso limitamos nosso domínio ao espaço tecnológico Java, de maneira que o escopo deste trabalho permaneça factível. Procede-se, aqui, portanto (1) identificando e definindo formalmente alguns modelos do espaço tecnológico Java, (2) identificando e formalizando algumas relações entre eles, criando uma rede de metamodelos a ser mantida sincronizada, e mostrando como essas relações trabalham através de um caso representativo, e por fim (3) discutindo a sincronização desta rede de metamodelos. Os resultados incluem a implementação dessas relações e o relatório sobre a experiência do desenvolvimento deste trabalho.The use of models in software engineering processes has grown in the last few years. And as it grows, grows also the relevance of some problems related to the realm. One of them is the model synchronization problem, that basically consists in keeping all the models of a software application consistent between themselves. In other words, the models of a software tend to be changed over its lifetime, and as it happens, these changes have to be properly forwarded to all the models regarding this software. For large software applications it is clearly inviable to perform such synchronization procedure manually, therefore, it is desired the creation of automatic methods able to synchronize the software’s models. We do not explore this problem for any kind of software, instead we limit our domain to the Java technological space, so that the scope of this thesis still remains feasible. This thesis thus proceeds by (1) identifying and formally defining some models of the Java technological space, (2) identifying and formalizing some relations between them, creating a network of metamodels supposed to be kept synchronized, and showing through a representative showcase how these relations work, and finally (3) discussing the synchronization of this network of metamodels. The outcomes include the implementation of these relations plus the report about the experience of developing it in this thesis
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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