It is well-known that many sub-attributes of line quality, such as edge raggedness, line waviness, etc., contribute to the perception of the overall line quality. But the relative importance of these sub-attributes is not clear, nor is there a method available for combining them into one representative number for overall line quality. To address these issues, we have designed and conducted a se...

Measuring broad emission-line widths in active galactic nuclei (AGN) is not straightforward owing to the complex nature of flux variability these systems. Line-width measurements become especially challenging when signal-to-noise low, profiles are narrower, or spectral resolution low. We conducted an extensive correlation analysis between from optical spectra Markarian 142 (Mrk 142; a narrow-li...

when power systems are expanded and connected together with weak tie lines, the low-frequency oscillations are increased and the stability margin of the power system decreases. therefore, when designing the transmission system to be used, it is necessary to maintain the dynamic stability of the power system, and to make sure to have the most possible stability margin. sssc is a facts device con...