Exploring initial challenges for green software engineering: summary of the first GREENS workshop, at ICSE 2012

The GREENS workshop provides a forum for practitioners and academics to share knowledge, ideas, practices and current results related to green and sustainable software engineering. This first workshop was held at ICSE 2012 in Zurich, Switzerland. It featured a keynote talk, twelve research position statements and two breakout sessions that discussed topics that ranged from bringing sustainability and energy efficiency into all software lifecycle stages, to green measures and estimations, practices, notations, and tools to both greening the software engineering process, and greening the resulting Information and Communication Technology systems. This report presents the themes of the workshop, summarizes the results of the discussions held in the breakout sessions, as well as the identified research challenge

Algorithms and Bounds for Drawing Directed Graphs

In this paper we present a new approach to visualize directed graphs and their hierarchies that completely departs from the classical four-phase framework of Sugiyama and computes readable hierarchical visualizations that contain the complete reachability information of a graph. Additionally, our approach has the advantage that only the necessary edges are drawn in the drawing, thus reducing the visual complexity of the resulting drawing. Furthermore, most problems involved in our framework require only polynomial time. Our framework offers a suite of solutions depending upon the requirements, and it consists of only two steps: (a) the cycle removal step (if the graph contains cycles) and (b) the channel decomposition and hierarchical drawing step. Our framework does not introduce any dummy vertices and it keeps the vertices of a channel vertically aligned. The time complexity of the main drawing algorithms of our framework is $O(kn)$, where $k$ is the number of channels, typically much smaller than $n$ (the number of vertices).Comment: Appears in the Proceedings of the 26th International Symposium on Graph Drawing and Network Visualization (GD 2018