Abstract: Operational frequency selection is a critical spot for ensuring high-frequency (HF) communication’s optimal quality, thus accurate prediction of usable frequency is essential to HF ...

Abstract: In the face of environmental deterioration and global climate change, the concept of carbon neutrality and carbon peaking has gained prominence as a means to balance development and ...

Men generally receive higher Social Security checks than women at all ages due to higher lifetime earnings. Very large sample data shows: at age 70, over 677,000 retirees receive an average of about ...