Search results
Results from the WOW.Com Content Network
A return period, also known as a recurrence interval or repeat interval, is an average time or an estimated average time between events such as earthquakes, floods, [1] landslides, [2] or river discharge flows to occur. It is a statistical measurement typically based on historic data over an extended period, and is used usually for risk analysis.
Graph showing wave height predictions using Wilson's formula (1965) Graph showing wave period predictions using Wilson's formula (1965) Goda adapted Wilson's formula with a simple equation which is first used to calculate the minimum fetch (F min): =
A power spectrum (magnitude-squared) of two sinusoidal basis functions, calculated by the periodogram method. Two power spectra (magnitude-squared) (rectangular and Hamming window functions plus background noise), calculated by the periodogram method.
The period (symbol T) is the interval of time between events, so the period is the reciprocal of the frequency: T = 1/f. [ 2 ] Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals ( sound ), radio waves , and light .
The significant wave height H 1/3 — the mean wave height of the highest third of the waves. The mean wave period, T 1. In addition to the short-term wave statistics presented above, long-term sea state statistics are often given as a joint frequency table of the significant wave height and the mean wave period.
Significant wave height H 1/3, or H s or H sig, as determined in the time domain, directly from the time series of the surface elevation, is defined as the average height of that one-third of the N measured waves having the greatest heights: [5] / = = where H m represents the individual wave heights, sorted into descending order of height as m increases from 1 to N.
k is the wave number: k = 2π/λ (radians per meter), ω is the angular frequency: ω = 2π/T (radians per second), x is the horizontal coordinate and the wave propagation direction (meters), z is the vertical coordinate, with the positive z direction pointing out of the fluid layer (meters), λ is the wave length (meters), T is the wave period .
An illustration of a periodic function with period . A periodic function, also called a periodic waveform (or simply periodic wave), is a function that repeats its values at regular intervals or periods. The repeatable part of the function or waveform is called a cycle. [1]