Beyond Real-world Benchmark Datasets: An Empirical Study of Node Classification with GNNs

Graph Neural Networks (GNNs) have achieved great success on a node classification task. Despite the broad interest in developing and evaluating GNNs, they have been assessed with limited benchmark datasets. As a result, the existing evaluation of GNNs lacks fine-grained analysis from various characteristics of graphs. Motivated by this, we conduct extensive experiments with a synthetic graph generator that can generate graphs having controlled characteristics for fine-grained analysis. Our empirical studies clarify the strengths and weaknesses of GNNs from four major characteristics of real-world graphs with class labels of nodes, i.e., 1) class size distributions (balanced vs. imbalanced), 2) edge connection proportions between classes (homophilic vs. heterophilic), 3) attribute values (biased vs. random), and 4) graph sizes (small vs. large). In addition, to foster future research on GNNs, we publicly release our codebase that allows users to evaluate various GNNs with various graphs. We hope this work offers interesting insights for future research.Comment: Accepted to NeurIPS 2022 Datasets and Benchmarks Track. 21 pages, 15 figure

Effect of disorder and vacancy defects on electrical transport properties of Co2MnGa thin films grown by magnetron sputtering

Co2MnGa is known as a Weyl semimetal exhibiting giant anomalous Hall and Nernst effects. However, the performance of Co2MnGa thin films grown on MgO(001) by the magnetron sputtering method is somewhat lower than that of the bulk crystals. Here, we attempted to improve the electrical transport properties by post-growth annealing at temperatures from 573 to 773 K. X-ray diffraction analysis indicated that the degree of long-range order changed from A2 to B2 plus L21 upon annealing at 673 K or above. Positron annihilation spectroscopy revealed the presence of high-density (≿100 ppm) divacancies, which were absent in the bulk crystal, and their partial improvement near the Co2MnGa/MgO interface on annealing at 673 K or above. Accompanying these structural changes, the longitudinal and anomalous Hall conductivities increased considerably and the anomalous Hall angle reached a maximum value of 11.8%. These findings imply that the post-growth annealing improved the electrical transport properties of Co2MnGa films through the development of long-range crystal order and reduction of divacancies. However, the electrical performance achieved by thermal annealing was still insufficient in comparison with the bulk crystals, and hence for further improvement, alternative approaches may need to be considered

Evaluation of the efficacy and safety of an integrated telerehabilitation platform for home-based cardiac REHABilitation in patients with heart failure (E-REHAB): protocol for a randomised controlled trial

Introduction Cardiac rehabilitation (CR) is strongly recommended as a medical treatment to improve the prognosis and quality of life of patients with heart failure (HF); however, participation rates in CR are low compared with other evidence-based treatments. One reason for this is the geographical distance between patients’ homes and hospitals. To address this issue, we developed an integrated telerehabilitation platform, RH-01, for home-based CR. We hypothesised that using the RH-01 platform for home-based CR would demonstrate non-inferiority compared with traditional centre-based CR.Methods and analysis The E-REHAB trial aims to evaluate the efficacy and safety of RH-01 for home-based CR compared with traditional centre-based CR for patients with HF. This clinical trial will be conducted under a prospective, randomised, controlled and non-inferiority design with a primary focus on HF patients. Further, to assess the generalisability of the results in HF to other cardiovascular disease (CVD), the study will also include patients with other CVDs. The trial will enrol 108 patients with HF and 20 patients with other CVD. Eligible HF patients will be randomly assigned to either traditional centre-based CR or home-based CR in a 1:1 fashion. Patients with other CVDs will not be randomised, as safety assessment will be the primary focus. The intervention group will receive a 12-week programme conducted two or three times per week consisting of a remotely supervised home-based CR programme using RH-01, while the control group will receive a traditional centre-based CR programme. The primary endpoint of this trial is change in 6 min walk distance.Ethics and dissemination The conduct of the study has been approved by an institutional review board at each participating site, and all patients will provide written informed consent before entry. The report of the study will be disseminated via scientific fora, including peer-reviewed publications and presentations at conferences.Trial registration number jRCT:2052200064