Department of Computer Science | Institute of Theoretical Computer Science | CADMO

Theory of Combinatorial Algorithms

Prof. Emo Welzl and Prof. Bernd Gärtner

Mittagsseminar (in cooperation with A. Steger, D. Steurer and B. Sudakov)

Mittagsseminar Talk Information

Date and Time: Tuesday, June 16, 2015, 12:15 pm

Duration: 30 minutes

Location: OAT S15/S16/S17

Speaker: Christof Lutteroth (University of Auckland)

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 effect on other constraints. In this talk I present a new formalism for constraint-based layouts, which we call a tiling algebra. Editing operations on layouts are specified as algebraic operations, 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 cover an interesting subset of layouts, called fragments, we show that there are more involved layouts, such as the pinwheel layout, which cannot be modeled with these operators alone. We introduce a third operator which is isomorphic to a Boolean conjunction. Finally we discuss symmetry properties and show the involutions of the semigroups and the isomorphism between both semigroups form the symmetry group D_4.


Upcoming talks     |     All previous talks     |     Talks by speaker     |     Upcoming talks in iCal format (beta version!)

Previous talks by year:   2024  2023  2022  2021  2020  2019  2018  2017  2016  2015  2014  2013  2012  2011  2010  2009  2008  2007  2006  2005  2004  2003  2002  2001  2000  1999  1998  1997  1996  

Information for students and suggested topics for student talks


Automatic MiSe System Software Version 1.4803M   |   admin login