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Polyphase Liposome
Polyphase may refer to: * Polyphase matrix, in signal processing * Polyphase system, in electrical engineering * Polyphasic sleep Biphasic sleep (or ''diphasic'', ''bifurcated'', or bimodal sleep) is the practice of sleeping during two periods over the course of 24 hours, while polyphasic sleep refers to sleeping multiple times—usually more than two. Each of these is in ... * Polyphase quadrature filter {{Disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphase Matrix
In signal processing, a polyphase matrix is a matrix whose elements are filter masks. It represents a filter bank as it is used in sub-band coders alias discrete wavelet transforms. If \scriptstyle h,\, g are two filters, then one level the traditional wavelet transform maps an input signal \scriptstyle a_0 to two output signals \scriptstyle a_1,\, d_1, each of the half length: :\begin a_1 &= (h \cdot a_0) \downarrow 2 \\ d_1 &= (g \cdot a_0) \downarrow 2 \end Note, that the dot means polynomial multiplication; i.e., convolution and \scriptstyle\downarrow means downsampling. If the above formula is implemented directly, you will compute values that are subsequently flushed by the down-sampling. You can avoid their computation by splitting the filters and the signal into even and odd indexed values before the wavelet transformation: :\begin h_\mbox &= h \downarrow 2 & a_ &= a_0 \downarrow 2 \\ h_\mbox &= (h \leftarrow 1) \downarrow 2 & a_ &= (a_0 \leftarro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphase System
A polyphase system is a means of distributing alternating-current (AC) electrical power where the power transfer is constant during each electrical cycle. AC phase refers to the phase offset value (in degrees) between AC in multiple conducting wires; ''phases'' may also refer to the corresponding terminals and conductors, as in color codes. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a defined phase between the voltage waves in each conductor; for three-phase voltage, the phase angle is 120° or 2π/3 radians (although early systems used 4 wire two-phase). Polyphase systems are particularly useful for transmitting power to electric motors which rely on alternating current to rotate. The most common example is the three-phase power system used for industrial applications and for power transmission. Compared to a single-phase, two-wire system, a three-phase three-wire system transmits three times as much power for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphasic Sleep
Biphasic sleep (or ''diphasic'', ''bifurcated'', or bimodal sleep) is the practice of sleeping during two periods over the course of 24 hours, while polyphasic sleep refers to sleeping multiple times—usually more than two. Each of these is in contrast to monophasic sleep, which is one period of sleep within 24 hours. Segmented sleep and divided sleep may refer to polyphasic or biphasic sleep, but may also refer to ''interrupted sleep'', where the sleep has one or several shorter periods of wakefulness, as was the norm for night sleep in pre-industrial societies. A common form of biphasic or polyphasic sleep includes a nap, which is a short period of sleep, typically taken between the hours of 9 am and 9 pm as an adjunct to the usual nocturnal sleep period. Napping behaviour during daytime hours is the simplest form of polyphasic sleep, especially when the nap(s) are taken on a daily basis. The term ''polyphasic sleep'' was first used in the early 20th century by psych ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
