Electromagnetic interference or EMI is any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronic or electrical equipment. It can be induced intentionally, as in some forms of electronic warfare, or unintentionally, as a result of spurious emissions and responses, intermodulation[?] products, and the like. It is also known as radio frequencyinterference.
... He, (1371-1435), Chinese admiral who travelled widely over the Indian Ocean and other seas, reaching Africa and Arabia and many other countries
See also explorations, ...