2,252 research outputs found
Increasing System Test Coverage in Production Automation Systems
An approach is introduced, which supports a testing technician in the
identification of possibly untested behavior of control software of fully
integrated automated production systems (aPS). Based on an approach for guided
semi-automatic system testing, execution traces are recorded during testing,
allowing a subsequent coverage assessment. As the behavior of an aPS is highly
dependent on the software, omitted system behavior can be identified and
assessed for criticality. Through close cooperation with industry, this
approach represents the first coverage assessment approach for system testing
in production automation to be applied on real industrial objects and evaluated
by industrial experts
Industrially Applicable System Regression Test Prioritization in Production Automation
When changes are performed on an automated production system (aPS), new
faults can be accidentally introduced in the system, which are called
regressions. A common method for finding these faults is regression testing. In
most cases, this regression testing process is performed under high time
pressure and on-site in a very uncomfortable environment. Until now, there is
no automated support for finding and prioritizing system test cases regarding
the fully integrated aPS that are suitable for finding regressions. Thus, the
testing technician has to rely on personal intuition and experience, possibly
choosing an inappropriate order of test cases, finding regressions at a very
late stage of the test run. Using a suitable prioritization, this iterative
process of finding and fixing regressions can be streamlined and a lot of time
can be saved by executing test cases likely to identify new regressions
earlier. Thus, an approach is presented in this paper that uses previously
acquired runtime data from past test executions and performs a change
identification and impact analysis to prioritize test cases that have a high
probability to unveil regressions caused by side effects of a system change.
The approach was developed in cooperation with reputable industrial partners
active in the field of aPS engineering, ensuring a development in line with
industrial requirements. An industrial case study and an expert evaluation were
performed, showing promising results.Comment: 13 pages, https://ieeexplore.ieee.org/abstract/document/8320514
On continuum modeling of sputter erosion under normal incidence: interplay between nonlocality and nonlinearity
Under specific experimental circumstances, sputter erosion on semiconductor
materials exhibits highly ordered hexagonal dot-like nanostructures. In a
recent attempt to theoretically understand this pattern forming process, Facsko
et al. [Phys. Rev. B 69, 153412 (2004)] suggested a nonlocal, damped
Kuramoto-Sivashinsky equation as a potential candidate for an adequate
continuum model of this self-organizing process. In this study we theoretically
investigate this proposal by (i) formally deriving such a nonlocal equation as
minimal model from balance considerations, (ii) showing that it can be exactly
mapped to a local, damped Kuramoto-Sivashinsky equation, and (iii) inspecting
the consequences of the resulting non-stationary erosion dynamics.Comment: 7 pages, 2 Postscript figures, accepted by Phys. Rev. B corrected
typos, few minor change
Automated root cause isolation in performance regression testing
Testing of software is an important aspect of software development. There exist multiple kinds of tests, like unit tests and integration tests. The tests this thesis will focus on will be load tests, which are used to observe a systemâs behavior under load. The presented approach will use these load tests in order to observe and analyze the performance of a system, like e.g. the response times of methods. Next these observations are compared with those made on other versions of the system, in order to detect performance regressions, deteriorations in performance, between versions. Another goal of the approach will be to identify the root cause of the regressions, which is the source code change responsible for introducing them. By doing this, the task of fixing this problem will be made easier for the software engineer, since he has an entry point for the problem.Das Testen von Software ist ein wichtiger Bestandteil der Software-Entwicklung. Es existieren viele Arten von Tests, wie Unit-Tests und Integrationstests. Die Tests, auf welche sich diese Thesis fokussiert, sind Lasttests. Diese werden genutzt um zu beobachten, wie ein System sich unter Belastung verhĂ€lt. Der vorgestellte Ansatz wird diese Lasttests nutzen, um das Betriebsverhalten eines Systems zu erfassen und analysieren, wie z.B. das Antwortzeitverhalten von einzelnen Methoden. Als NĂ€chstes werden diese Beobachtungen mit denen verglichen, die auf anderen Versionen des Systems gemacht wurden, um Regressionen im Betriebsverhalten, wie Verschlechterungen des Antwortzeitverhaltens, zwischen den Versionen zu finden. Ein weiteres Ziel des Ansatzes wird es sein, die Hauptursache einer Regression zu identifizieren, welches die QuellcodeĂ€nderung ist, die fuÌr die EinfuÌhrung der Regression verantwortlich ist. Dies wird es dem Software-Entwickler, der beauftragt wurde die Regression zu verbessern, einfacher machen dies zu tun, da er bereits einen festen Ansatzpunkt geliefert bekommen hat
Ăber das MaĂ der entkommenden Menge eines quasiregulĂ€ren Analogons des Sinus
Quasiregular maps are a natural generalisation of holomorphic maps to higher dimensions. Recently, there is an increasing interest in studying the dynamics of quasiregular maps on the -dimensional Euclidian space. Until now, not much is known about the dynamical behaviour of general quasiregular maps. However, quasiregular analogues of the complex exponential map as well as of trigonometric functions have been constructed and turned out to behave quite similarly to their counterparts in the plane.
In this thesis, we examine the dynamical behaviour of certain quasiregular maps on the -dimensional Euclidian space which can be seen as quasiregular analogues of complex trigonometric functions. This class was introduced by Bergweiler and Eremenko in 2011. We will denote a member of this class by \Sin(x). We are interested in the iteration of these maps, in particular in the escaping set consisting of all points that tend to infinity under iteration.\\
We prove the following results: Theorem 1 is an analogue of a well known result by McMullen from 1987. We show that for f(x)=\lambda\Sin(x), where , the escaping set has positive Lebesgue measure. In fact, this is also true for the fast escaping set consisting of all points that essentially escape as fast as possible.\\
Theorem 2 states that the measure of the non-escaping set of in vertical square beams is finite. This corresponds to a result in the plane by Schubert from 2008 concerning the escaping set of in vertical strips. Again, this is also true for the fast escaping set.\\
We also use the map \Sin(x) to construct a quasiregular power mapping which is similar to a quasiregular power mapping introduced by Mayer based on Zorich maps. We discuss some properties of the map .
Theorem 3 then states that for , the composition of the power mapping with a suitable quasiregular analogue of the trigonometric functions yields a quasiregular map with non-escaping set of finite measure. This generalises a result by Hemke from 2005. In the last section, we discuss the sharpness of Theorem 3.QuasiregulĂ€re Abbildungen sind eine natĂŒrliche Verallgemeinerung holomorpher Abbildungen auf höhere Dimensionen. In letzter Zeit gibt es ein zunehmendes Interesse an der Untersuchung des dynamischen Verhaltens von quasiregulĂ€ren Abbildungen auf dem -dimensionalen euklidischen Raum. Noch ist nicht viel ĂŒber das dynamische Verhalten von allgemeinen quasiregulĂ€ren Abbildungen bekannt. Allerdings wurden quasiregulĂ€re Analoga der komplexen Exponentialabbildung sowie von trigonometrischen Funktionen konstruiert, welche sich aus dynamischer Sicht sehr Ă€hnlich wie ihre GegenstĂŒcke in der Ebene verhalten.
In dieser Arbeit untersuchen wir das dynamische Verhalten von bestimmten quasiregulĂ€ren Abbildungen auf dem -dimensionalen euklidischen Raum, welche als quasiregulĂ€re Analoga von komplexen trigonometrischen Funktionen angesehen werden können. Diese Klasse wurde von Bergweiler und Eremenko im Jahr 2011 eingefĂŒhrt. Wir bezeich\-nen eine Abbildung dieser Klasse mit \Sin(x). Wir interessieren uns fĂŒr die Iteration dieser Abbildungen, insbesondere fĂŒr die entkommende Menge bestehend aus all jenen Punkten, welche unter Iteration nach unendlich streben.\\
Wir beweisen die folgenden Ergebnisse: Theorem 1 ist ein Analogon von einem bekann\-ten Resultat von McMullen aus dem Jahr 1987. Wir zeigen, dass die entkommende Menge von f(x)=\lambda\Sin(x) fĂŒr alle positives LebesguemaĂ hat. In der Tat stimmt dies auch fĂŒr die schnell entkommende Menge , welche die Punkte enthĂ€lt, die im Wesentlichen so schnell wie möglich entkommen.\\
Theorem 2 besagt, dass das MaĂ der nichtentkommenden Menge von in vertikalen Balken endlich ist. Dies entspricht einem Resultat in der Ebene von Schubert aus dem Jahr 2008 ĂŒber die entkommende Menge von in vertikalen Streifen. Theorem 2 gilt ebenfalls fĂŒr die schnell entkommende Menge.\\
AuĂerdem verwenden wir die Abbildung \Sin(x) um eine quasiregulĂ€re Potenzfunktion zu konstruieren. Diese Abbildung Ă€hnelt einer von Mayer vorgestellten quasire\-gulĂ€ren Potenzfunktion, welche auf Zorich Abbildungen aufbaut. Wir diskutieren einige Eigenschaften der Abbildung .
Theorem 3 besagt schlieĂlich, dass die Komposition von mit einem geeigneten quasiregulĂ€ren Analogon der trigonometrischen Funktionen eine quasiregulĂ€re Abbildung mit nichtentkommender Menge von endlichem MaĂ ergibt, sofern . Dies verallgemeinert ein Ergebnis von Hemke aus dem Jahr 2005. Im letzten Abschnitt diskutieren wir die SchĂ€rfe von Theorem 3
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