Many studies have argued that relative income predicts individual well-being. More recently, it has been suggested that the relative rank of an individual’s income, rather than how that income compares to a mean or reference income, is important. Here the relative rank hypothesis is examined along with the additional hypothesis that individuals compare their incomes predominantly with those of ...

Rooted trees are usually drawn planar and upward, i.e., without crossings and without any parent placed below its child. In this paper we investigate the area requirement of planar upward drawings of rooted trees. We give tight upper and lower bounds on the area of various types of drawings, and provide linear-time algorithms for constructing optimal area drawings. Let T be a bounded-degree roo...

Canonical orderings serve as the basis for many incremental planar drawing algorithms. All these techniques, however, have in common that they are limited to undirected graphs. While st-orderings do extend to directed graphs, especially planar st-graphs, they do not offer the same properties as canonical orderings. In this work we extend the so called bitonic st-orderings to directed graphs. We...

Article history: Received 8 September 2011 Accepted 23 November 2012 Available online 27 November 2012 Communicated by D. Wagner

it has been proved that sphericity testing for digraphs is an np-complete problem. here, we investigate sphericity of 3-connected single source digraphs. we provide a new combinatorial characterization of sphericity and give a linear time algorithm for sphericity testing. our algorithm tests whether a 3-connected single source digraph with $n$ vertices is spherical in $o(n)$ time.

Objectives: The purpose of this study was to compare scapular kinematics during elevation phase of abduction, flexion, and scapular plane elevation phase between fifteen persons with shoulder impingement syndrome (SIS) and thirteen persons without it. Methods: Values of scapular kinematics include scapular superior and lateral translations, upward rotation, external rotation, and posterior t...

Upward planar drawings of digraphs are crossing free drawings where all edges flow in the upward direction. The problem of deciding whether a digraph admits an upward planar drawing is called the upward planarity testing problem, and it has been widely studied in the literature. In this paper we investigate a new upward planarity testing problem, that is, deciding whether a digraph admits an up...

A potential source of high energy neutrinos is the annihilation of Weakly Interacting Massive Particles (WIMPs) collecting in gravitational potential wells such as the centers of the Earth, the Sun, or the Galaxy. A search for such a WIMP annihilation signal using the Super-Kamiokande (SuperK) detector is presented. Super-K observes 1.1 upward throughgoing muons per day. These events are caused...