152 research outputs found
Automation of Java Code Analysis for Programming Exercises
In this paper we present a tool environment for semi-automatic verification of basic programming exercises. We describe how graph transformation can be used for analysis of code structures and present an example from a current course
eine graphbasierte Sprache zur Spezifikation komplexer Suchmuster für die statische Quelltextanalyse
Das Ziel dieser Arbeit ist die Darstellung einer graphbasierten Sprache für die Beschreibung komplexer Suchmuster zur Quelltextanalyse. Der Fokus liegt auf der Möglichkeit einer modularisierten Musterspezifikation, so dass der Nutzer komplexe Muster über die Kombination einzelner Module erstellen kann. Die Sprachsyntax basiert sowohl auf dem Abstrakten Syntaxbaum, als auch auf Elementen der Graphtypen Kontrollabhängigkeitsgraph und Datenabhängigkeitsgraph. Somit kann in einer Musterspezifikation die Graphrepräsentation von Java Syntaxelementen mit abstrakteren Abhängigkeitsbeziehungen kombiniert werden
Gemeinsam zur Musik : eine qualitative Studie über Jugendliche mit Lernbeeinträchtigungen als Teilnehmende an Musikgruppen in der Inklusion
[no abstract
La fiesta del Chivo: cambio y continuidad en la obra de Mario Vargas Llosa
Con su novela La fiesta del Chivo (2000), que tiene como tema el fin violento de la era del dictador Rafael Leonidas Trujillo en la República Dominicana, Mario Vargas Llosa retorna a sus primeras obras de carácter político y socio-crítico, sobre todo a Conversación en la Catedral (1969), donde ya había explorado los mecanismos del poder de un régimen autoritario y sus efectos en la vida del individuo. Contrariamente a sus obras anteriores, La fiesta del Chivo fue recibida con unánime entusiasmo, suscitando un sinnúmero de reseñas y comentarios
Unimodal spline regression and its use in various applications with single or multiple modes
Research in the field of non-parametric shape constrained regression has been extensive and there is need for such methods in various application areas, since shape constraints can reflect prior knowledge about the underlying relationship. This thesis develops semi-parametric spline regression approaches to unimodal regression.
However, the prior knowledge in different applications is also of increasing complexity and data shapes may vary from few to plenty of modes and from piecewise unimodal to accumulations of identically or diversely shaped unimodal functions. Thus, we also go beyond unimodal regression in this thesis and propose to capture multimodality by employing piecewise unimodal regression or deconvolution models based on unimodal peak shapes.
More explicitly, this thesis proposes unimodal spline regression methods that make use of Bernstein-Schoenberg-splines and their shape preservation property. To achieve unimodal and smooth solutions we use penalized splines, and extend the penalized spline approach towards penalizing against general parametric functions, instead of using just difference penalties. For tuning parameter selection under a unimodality constraint a restricted maximum likelihood and an alternative Bayesian approach for unimodal regression are developed. We compare the proposed methodologies to other common approaches in a simulation study and apply it to a dose-response data set. All results suggest that the unimodality constraint or the combination of unimodality and a penalty can substantially improve estimation of the functional relationship.
A common feature of the approaches to multimodal regression is that the response variable is modelled using several unimodal spline regressions. This thesis examines mixture models of unimodal regressions, piecewise unimodal regression and deconvolution models with identical or diverse unimodal peak shapes. The usefulness of these extensions of unimodal regression is demonstrated by applying them to data sets from three different application areas: marine biology, astroparticle physics and breath gas analysis.
The proposed methodologies are implemented in the statistical software environment R and the implementations and their usage are explained in this thesis as well
Wettbewerbspolitischer Handlungsbedarf bei der Verknüpfung von zweiseitigen Märkten im Internet: Der Fall Google
We discuss competition effects and possible regulation of vertical integration in internet-based two-sided markets against the background of the ongoing antitrust allegations against Google. In such markets, network effects and economics of scale often lead to dominating companies which are integrated over several markets. Although implying efficiency gains, the (dynamic) network effects and economics of scale may also create significant barriers to entry. These barriers of entry can be lowered if entrants can appropriate (parts of) the dynamic effects accumulated by the incumbents. At the same time, such externalities reduce incentives to invest in dynamic effects in the first place. Measures by firms that deter multi homing, increase switching costs or create incompatibilities are anti-competitive and should thus be prohibited. Systematic top listing of own products in the search results can leverage market power and reduce competition. However, there is yet no appropriate economic theory on the power’ of search engines. The often used concept of ‘search neutrality’ is not convincing
Wettbewerbspolitischer Handlungsbedarf bei der Verknüpfung von zweiseitigen Märkten im Internet: Der Fall Google
We discuss competition effects and possible regulation of vertical integration in internet-based two-sided markets against the background of the ongoing antitrust allegations against Google. In such markets, network effects and economics of scale often lead to dominating companies which are integrated over several markets. Although implying efficiency gains, the (dynamic) network effects and economics of scale may also create significant barriers to entry. These barriers of entry can be lowered if entrants can appropriate (parts of) the dynamic effects accumulated by the incumbents. At the same time, such externalities reduce incentives to invest in dynamic effects in the first place. Measures by firms that deter multi homing, increase switching costs or create incompatibilities are anti-competitive and should thus be prohibited. Systematic top listing of own products in the search results can leverage market power and reduce competition. However, there is yet no appropriate economic theory on the power’ of search engines. The often used concept of ‘search neutrality’ is not convincing
Controlled oleosome extraction to produce a plant-based mayonnaise-like emulsion using solely rapeseed seeds
Oleosomes are oil storage structures in seeds, consisting of triglycerides surrounded by a protein-phospholipid mixed monolayer. They can be extracted aqueously together with other seed components such as proteins and soluble fibers. The co-extracted biomolecules can affect the properties of the extracts. Nevertheless, it is possible to control the electrostatic and hydrophobic interactions between these biomolecules and oleosomes by adjusting the extraction conditions. Hence, our aim was to adjust the extraction conditions in order to recover a natural emulsion with a specific functionality: a plant-based mayonnaise-like product, derived solely from rapeseed seeds. By varying the pH of extraction, the droplet size was customized and by increasing the number of purification steps, the right amount of co-extracted material was removed. A combination of these conditions shifted the rheological properties of the obtained natural emulsion to a range similar to the benchmark mayonnaises. This work shows that it is feasible to produce a plant-based mayonnaise with an oil content ranging from 61.7 g/100g to 72.0 g/100g through a simple and continuous oleosome extraction process by controlling the interactions between oleosomes and co-extracted material.</p
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