Tiling Algebra for Constraint-based Layout Editing

The constraint-based layout model is a very powerful model to describe a wide range of graphical user interface (GUI) layouts, based on linear constraints. However, the advantages of the constraint-based layout model come at a price: layout designers have to ensure layouts are sound, i.e., they are solvable and items in the layout do not overlap each other. Keeping a layout sound is non-trivial since editing one constraint may have undesirable effects on other constraints.In this article, we propose a new formalism for constraint-basedlayouts which we call a tiling algebra. Editing operations on layouts are specified algebraically, which guarantees that these operations keep a layout sound. We propose to model tiling operations with two operators that are isomorphic cancellative semigroup operators with involution if seen as binary operators. While these semigroup operators alone already cover an interesting subset of layouts, called fragments, we show that there are more involved layouts, such as the pinwheel layout, which cannot be modelled with these operators alone. For this reason we introduce a third operator which is isomorphic to a Boolean conjunction.Our approach helps to describe constraint-based layoutscorrectly and to make layout editing robust. We apply the proposed algebra to two real constraint-basedsystems, which illustrate how it can be used to support sound layout creation and modification

Studie zum Nachweis angeregter Myonen mit dem CMS-Detektor

In dieser Diplomarbeit werden die Möglichkeiten untersucht, die der zukünftige CMS- DetektoramLHCbeiderSuchenachangeregtenMyonenµ∗ bietet.Dazuwirddergoldene Zerfallskanal des angeregten Myons µ∗ → µ + γ betrachtet. Da sich der LHC und der CMS-Detektor noch im Bau benden, wird eine Machbarkeits- studie durchgeführt, wobei die Erzeugung sowie der Zerfall des µ∗ und auch der relevanten Untergrundprozesse mit Hilfe einer Computersimulation beschrieben wird. Um den Durch- gang der Signal- und Untergrund-Teilchen durch den CMS-Detektor zu studieren, wird die volle CMS-Detektorsimulation verwendet. Mit Hilfe der späteren CMS-Rekonstruktions- Software ist es dann möglich, Daten zu erhalten, wie sie auch später vom realen Detektor aufgenommen sein könnten. Aus diesen Daten wird das µ∗ rekonstruiert. Zur statistischen Auswertung der so erhaltenen Daten wird die Loglikelihood-Verhältnis-Methode verwen- det. Als Ergebnis dieser Arbeit wurde ein Entdeckungspotential sowie eine Ausschlussgrenze berechnet. Somit ist es möglich, bei einer integrierten LHC-Luminosität von 10fb−1 mit dem CMS-Detektor angeregte Myonen bei einem Skalenparameter von Λ=1 TeV bis zu einerMassevon3,50TeVzu entdeckenundbiszueiner Massevon3,81TeVauszuschlieÿen. Damit kann die aktuelle Ausschlussgrenze von 618 GeV (Λ=1 TeV) mit CMS deutlich angehoben werden

An Evaluation of Stacking and Tiling Features within the Traditional Desktop Metaphor

Abstract. Having many open windows on the desktop can lead to various usability problems. Window content may get occluded by other windows and working with multiple windows may get cumbersome. In this paper, we evaluate the idea to integrate stacking and tiling features into the traditional desktop metaphor. For this purpose we introduce the Stack & Tile window manager, which allows users to stack and tile arbitrary windows into groups that can be moved and resized similar to single windows. To evaluate if stacking and tiling can improve productivity, we conducted an experimental evaluation. We found that participants were able to perform various multi-window tasks and switch between tasks significantly faster using Stack & Tile. Furthermore, we found that the time to set up a Stack & Tile window group is reasonably low. Stack & Tile is open-source and has been used for over two years now. To evaluate its usefulness in practice, we conducted a web-based survey that reveals how people are actually using the new stacking and tiling features

Automatic generation of user interface layouts for alternative screen orientations

Creating multiple layout alternatives for graphical user interfaces to accommodate different screen orientations for mobile devices is labor intensive. Here, we investigate how such layout alternatives can be generated automatically from an initial layout. Providing good layout alternatives can inspire developers in their design work and support them to create adaptive layouts. We performed an analysis of layout alternatives in existing apps and identified common realworld layout transformation patterns. Based on these patterns we developed a prototype that generates landscape and portrait layout alternatives for an initial layout. In general, there is a very large number of possibilities of how widgets can be rearranged. For this reason we developed a classification method to identify and evaluate “good” layout alternatives automatically. From this set of “good” layout alternatives, designers can choose suitable layouts for their applications. In a questionnaire study we verified that our method generates layout alternatives that appear well structured and are easy to use