A Sparse Stress Model

Force-directed layout methods constitute the most common approach to draw general graphs. Among them, stress minimization produces layouts of comparatively high quality but also imposes comparatively high computational demands. We propose a speed-up method based on the aggregation of terms in the objective function. It is akin to aggregate repulsion from far-away nodes during spring embedding but transfers the idea from the layout space into a preprocessing phase. An initial experimental study informs a method to select representatives, and subsequent more extensive experiments indicate that our method yields better approximations of minimum-stress layouts in less time than related methods.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Modularity clustering is force-directed layout

Two natural and widely used representations for the community structure of networks are clusterings, which partition the vertex set into disjoint subsets, and layouts, which assign the vertices to positions in a metric space. This paper unifies prominent characterizations of layout quality and clustering quality, by showing that energy models of pairwise attraction and repulsion subsume Newman and Girvan's modularity measure. Layouts with optimal energy are relaxations of, and are thus consistent with, clusterings with optimal modularity, which is of practical relevance because both representations are complementary and often used together.Comment: 9 pages, 7 figures, see http://code.google.com/p/linloglayout/ for downloading the graph clustering and layout softwar

Application of Approximate Pattern Matching in Two Dimensional Spaces to Grid Layout for Biochemical Network Maps

Background For visualizing large-scale biochemical network maps, it is important to calculate the coordinates of molecular nodes quickly and to enhance the understanding or traceability of them. The grid layout is effective in drawing compact, orderly, balanced network maps with node label spaces, but existing grid layout algorithms often require a high computational cost because they have to consider complicated positional constraints through the entire optimization process. Results We propose a hybrid grid layout algorithm that consists of a non-grid, fast layout (preprocessor) algorithm and an approximate pattern matching algorithm that distributes the resultant preprocessed nodes on square grid points. To demonstrate the feasibility of the hybrid layout algorithm, it is characterized in terms of the calculation time, numbers of edge-edge and node-edge crossings, relative edge lengths, and F-measures. The proposed algorithm achieves outstanding performances compared with other existing grid layouts. Conclusions Use of an approximate pattern matching algorithm quickly redistributes the laid-out nodes by fast, non-grid algorithms on the square grid points, while preserving the topological relationships among the nodes. The proposed algorithm is a novel use of the pattern matching, thereby providing a breakthrough for grid layout. This application program can be freely downloaded from http://www.cadlive.jp/hybridlayout/hybridlayout.html

The relationship between mood and sleep in different female reproductive states

Peer reviewe

The beneficial effects of massage therapy for insomnia in postmenopausal women

With increases life expectancy, the incidence of undesirable manifestations of menopause has increased as well. The effects of lost ovarian function include progressive decrease in estradiol secretion, trophic changes in the breast, vasomotor symptoms, anxiety, depression, and sleep disorders. Insomnia, which has physiological consequences and can result in a loss of quality of life, is prevalent in women after menopause. Hormone therapy has been widely used to reduce menopausal symptoms, but its use in recent years has been questioned because of the reported risks of cardiovascular events and increased incidence of tumors. This controversy has generated significant interest in non-hormonal treatments among both physicians and patients. Our previous research has shown a positive effect of massage therapy on menopausal symptoms. We explored the hypothesis that massage therapy would produce beneficial effects in postmenopausal women through inflammatory and immunological changes. Recent results from self-report questionnaires have shown improvements in sleep pattern and quality of life following massage therapy. These findings demonstrate the effectiveness of massage therapy for the treatment of postmenopausal symptoms, particularly insomnia, and indicate that it is a promising line of research