AUTHOR=Zhao Wenxin , Liu Xubin , Wu Yujie , Zhang Tao , Zhang Luao TITLE=A Learning-to-Rank-Based Investment Portfolio Optimization Framework for Smart Grid Planning JOURNAL=Frontiers in Energy Research VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.852520 DOI=10.3389/fenrg.2022.852520 ISSN=2296-598X