Abstract: I welcome you to the fourth issue of the IEEE Communications Surveys and Tutorials in 2021. This issue includes 23 papers covering different aspects of communication networks. In particular, ...

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Khadija Khartit is a strategy, investment, and funding expert, and an educator of fintech ...

Abstract: Ultrasonic transducers with broad bandwidth are considered to have high axial resolution and good ultrasound scanning flexibility for the clinical applications. The limitations of spatial ...