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, ...

Abstract: Gaussian functions are suitable for describing many processes in mathematics, science, and engineering, making them very useful in the fields of signal and image processing. For example, the ...

Aggregate functions help turn large datasets into simple summaries used across many fields. GROUP BY and HAVING allow structured grouping and filtering of data for clearer reports. Functions like ...