The gravitational-wave detector is a very complicated and sensitive
collection of advanced instruments, which is influenced not only by the mutual
interaction between mechanical/electronics systems but also by the surrounding
environment. Thus, it is necessary to categorize and reduce noises from many
channels interconnected by such instruments and environment for achieving the
detection of gravitational waves because it enhances to increase of a
signal-to-noise ratio and reduces false alarms from coincident loud events. For
this reason, it is of great importance to identify some coherent associations
between complicated channels. This study presents a way of identifying (non-)
linear couplings between interconnected channels by using some correlation
coefficients, which are applied to practical issues such as noises by hardware
injection test, lightning strokes, and air compressor vibrations
gravitational-wave detector.Comment: 10 pages, 8 figures, and 2 table