Another particularly common group of microscopic animals are the rotifers, which are filter feeders that are usually found in fresh water.

* Bessel filter – best pulse response for a given order because it has no group delay ripple

* Gaussian filter – minimum group delay ; gives no overshoot to a step function.

The mouth of polychaetes varies in form depending on their diet, since the group includes predators, herbivores, filter feeders, scavengers, and parasites.

So automated Internet surveillance computers sift through the vast amount of intercepted Internet traffic, and filter out and report to human investigators those bits of information which are " interesting "— such as the use of certain words or phrases, visiting certain types of web sites, or communicating via email or chat with a certain individual or group.

* The filter should have a specific phase shift or group delay

* A fractional delay filter is an all-pass that has a specified and constant group or phase delay for all frequencies.

This e. g. allows the design of zero delay recursive filter, where the group delay of a causal filter is canceled by its Hermitian non-causal filter.

* A Bessel filter ( i. e., continuous-time filter with flattest group delay ) has an underdamped.

Gain and group delay of a fifth-order type I Chebyshev filter with ε = 0. 5.

The gain and the group delay for a fifth-order type I Chebyshev filter with ε = 0. 5 are plotted in the graph on the left.

Gain and group delay of a fifth-order type II Chebyshev filter with ε = 0. 1.

The gain and the group delay for a fifth-order type II Chebyshev filter with ε = 0. 1 are plotted in the graph on the left.

They have a wide range of diets, and the group includes carnivores, herbivores, scavengers and filter feeders.

Standard features included directional signals, full-flow oil filter, dual speed electric windshield washer / wipers, Deluxe steering wheel, cigar lighter, Step-on parking brake, dual armrests, Turbine-Drive transmission, padded dashboard, heater, defroster, glovebox light, back-up lights, power steering, Glare-proof rearview mirror, power brakes, power brake signal light, safety buzer, courtesy lights, two-way power seats, power windows, Super Deluxe wheelcovers, Safety option group, custom padded cushions, Accessory Group options and custom moldings.

Standard equipment included directional signals, full-flow oil filter, dual speed electric windshield wiper / washers, Deluxe steering wheel, cigar lighter, Step-On parking brake, dual armrests, Turbine-Drive automatic transmission, padded dashboard, heater, defroster, glovebox light, back-up lights, power steering, Glare-proof rearview mirror, power brakes, parking brake signal light, safety buzzer, courtesy lights, two-way power seats, power windows, Super Deluxe wheelcovers, Safety option group, custom padded cushions, Accessory Group options and custom moldings.

Gain and group delay of the third-order Butterworth filter with ω < sub > c </ sub >= 1

* Any uniform space ( hence any metric space, topological vector space, or topological group ) is a Cauchy space ; see Cauchy filter for definitions.

* Offer a new way to filter, order, or group data by using a field not exposed in the default functions of the original design.

Since a linear phase ( or generalized linear phase ) filter has constant group delay, all frequency components have equal delay times.

By contrast, a filter with non-linear phase has a group delay that varies with frequency, resulting in phase distortion.

A non-causal filter can usually be changed into a causal filter by adding a delay to it.

Another advantage of FIR filters is that their impulse response can be made symmetric, which implies a response in the frequency domain which has zero phase at all frequencies ( not considering a finite delay ), which is absolutely impossible with any IIR filter.

A discrete-time FIR filter of order N. The top part is an N-sample delay line ; each delay step is denoted z < sup >- 1 </ sup >.

An N < sup > th </ sup > order FIR filter can be implemented in a discrete time system using a computer program or specialized hardware in which the input signal is subject to N delay stages.

A general finite impulse response filter with n stages, each with an independent delay, d < sub > i </ sub >, and amplification gain, a < sub > i </ sub >.

In general, this form requires 2N delay elements ( for both input and output signals ) for a filter of order N.

The alternate Direct Form II only needs N delay units, where N is the order of the filter – potentially half as much as Direct Form I.

Cascading direct form II sections result in N delay elements for filter order of N. Cascading direct form I sections result in N + 2 delay elements since the delay elements of the input of any section ( except the first section ) are a redundant with the delay elements of the output of the preceding section.

If F is a linear function, for instance a filter whose gain and / or delay varies with frequency, then the signal will experience linear distortion.

Although it is useful to view this as a subtractive synthesis technique based on a feedback loop similar to that of a comb filter for z-transform analysis, it is better viewed as the simplest of a class of wavetable-modification algorithms now known as digital waveguide synthesis, as the delay line acts to store one period of the signal.

# The output of the delay line is fed through a filter.

The fundamental frequency ( specifically, the lowest nonzero resonant frequency ) of the resulting signal is the lowest frequency at which the unwrapped phase response of the delay and filter in cascade is.

The filter would therefore need to have infinite delay, or knowledge of the infinite future and past, in order to perform the convolution.

This can also have the problem of heavy DNS lookup load for no useful results, but it may not delay mail as much because scoring makes it possible for lookups to be done in parallel and asynchronously while the filter is checking the message against the other rules.

They can have several oscillators with pulse width modulated waveforms, frequency-and amplitude-modulation, ADSR envelope forming and a number of digital sound processing effects like filter, exciter, delay, chorus and reverb.

A stiff physical barrier tends to reflect higher sound frequencies, and so acts as a low-pass filter for transmitting sound.

Because it requires large ( i. e., fast ) changes and tends to quickly forget its prior output values, it can only pass relatively high frequencies, as would be expected with a high-pass filter with a small.

Hydrostatic pressure within blood vessels tends to cause water to filter out into the tissue.

The air intake filter tends to clog up with sawdust.

The high prestige dialect ( or language ) tends to be the more formalised, and its forms and vocabulary often ' filter down ' into the vernacular, though often in a changed form.

In the Citroën set-up the adverse effect is that the car tends to roll a lot ( the oil is pushed from one side to the other ) however this is filtered by the anti roll bar ( there's no equivalent item on the Princess to filter front-rear balance, though this issue was addressed on later versions of that suspension ).

One way to reduce rumble is to make the turntable very heavy, so that it acts as mechanical damper or low-pass filter, but even with the best turntables a lot of rumble tends to be generated by warped records or pressing irregularities sometimes visible as ‘ bobbles ’ in the surface.