The most common speech coding scheme is Code Excited Linear Prediction ( CELP ) coding, which is used for example in the GSM standard.

This is a reference to compare the monophonic ( not stereophonic ) audio quality and compression bitrates of the different codecs available for files including PCM, ADPCM, Microsoft GSM 06. 10, CELP, SBC, Truespeech and MPEG Layer-3.

It is based on the CELP speech coding algorithm.

One of the main reasons is that CELP has long proven that it could do the job and scale well to both low bit rates ( as evidenced by DoD CELP @ 4. 8 kbit / s ) and high bit rates ( as with G. 728 @ 16 kbit / s ).

* MPEG-4 CELP which is a parametric coder suited for voice only ( vocoder ) but that is robust to errors and needs a small bit rate.

* MPEG-4 HVXC which is also a parametric coder for speech programs that uses an even smaller bitrate than CELP.

The ACELP method is widely employed in current speech coding standards such as AMR, EFR, AMR-WB ( G. 722. 2 ), VMR-WB, EVRC, EVRC-B, SMV, TETRA, PCS 1900, MPEG-4 CELP and ITU-T G-series standards G. 729, G. 729. 1 ( first coding stage ) and G. 723. 1.

The essence of CELP techniques, which is an analysis-by-synthesis approach to codebook search, is retained in LD-CELP.

The full rate and half rate are based on the CELP algorithm that is based on a combined closed-loop-open-loop-analysis ( COLA ).

Currently, the CELP algorithm is used.

The variation of CELP used in the FS-1016 is so-called ternary codebook, meaning that all excitation amplitudes are either + 1 ,-1 or 0.

Code-excited linear prediction ( CELP ) is a speech coding algorithm originally proposed by M. R.

Along with its variants, such as algebraic CELP, relaxed CELP, low-delay CELP and vector sum excited linear prediction, it is currently the most widely used speech coding algorithm.

CELP is commonly used as a generic term for a class of algorithms and not for a particular codec.

The CELP algorithm is based on four main ideas:

The main principle behind CELP is called Analysis-by-Synthesis ( AbS ) and means that the encoding ( analysis ) is performed by perceptually optimizing the decoded ( synthesis ) signal in a closed loop.

In order to achieve real-time encoding using limited computing resources, the CELP search is broken down into smaller, more manageable, sequential searches using a simple perceptual weighting function.

MPEG-4 Natural Speech Coding Tool Set uses two algorithms: HVXC and CELP ( Code Excited Linear Prediction ).

* G. 718-uses CELP for the lower two layers for the band ( 50 – 6400 Hz ) in a two stage coding structure

* Code-excited linear prediction ( CELP ), 2400 and 4800 bit / s, Federal Standard 1016, used in STU-III

* M. R. Schroeder and B. S. Atal, " Code-excited linear prediction ( CELP ): high-quality speech at very low bit rates ," in Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing ( ICASSP ), vol.

All this led to the choice of Code Excited Linear Prediction ( CELP ) as the encoding technique to use for Speex.

The MPEG-4 Part 3 consists of a variety of audio coding technologies-from lossy speech coding ( HVXC, CELP ), general audio coding ( AAC, TwinVQ, BSAC ), lossless audio compression ( MPEG-4 SLS, Audio Lossless Coding, MPEG-4 DST ), a Text-To-Speech Interface ( TTSI ), Structured Audio ( using SAOL, SASL, MIDI ) and many additional audio synthesis and coding techniques.

The slot that the COASt module plugged into was named " CELP ", or " card edge low profile ", referring to the small circuit board and the conductors on its edge.

As part of NATO testing for new NATO standard, MELPe was tested against other candidates such as France's HSX ( Harmonic Stochastic eXcitation ) and Turkey's SB-LPC ( Split-Band Linear Predictive Coding ), as well as the old secure voice standards such as FS1015 LPC-10e ( 2. 4 kbit / s ), FS1016 CELP ( 4. 8 kbit / s ) and CVSD ( 16 kbit / s ).

Therefore, four loose families of more-efficient light transport modelling techniques have emerged: rasterization, including scanline rendering, geometrically projects objects in the scene to an image plane, without advanced optical effects ; ray casting considers the scene as observed from a specific point-of-view, calculating the observed image based only on geometry and very basic optical laws of reflection intensity, and perhaps using Monte Carlo techniques to reduce artifacts ; and ray tracing is similar to ray casting, but employs more advanced optical simulation, and usually uses Monte Carlo techniques to obtain more realistic results at a speed that is often orders of magnitude slower.

A normal relational database however, is not efficient for business intelligence reports where dimensional modelling is prevalent.

Although several versions of many-worlds have been proposed since Hugh Everett's original work, they all contain one key idea: the equations of physics that model the time evolution of systems without embedded observers are sufficient for modelling systems which do contain observers ; in particular there is no observation-triggered wave function collapse which the Copenhagen interpretation proposes.

Images and other outputs of modelling are normally referred to as being " fractals " even if they do not have strictly fractal characteristics, such as when it is possible to zoom into a region of the fractal image that does not exhibit any fractal properties.

The field is largely focused on the modelling of derivatives, although other important subfields include insurance mathematics and quantitative portfolio problems.

Much of the development during the quantitative revolution is now apparent in the use of Geographic information systems ; the use of statistics, spatial modelling and positivist approaches is still important to many branches of human geography.

Falwell added " role modelling the gay lifestyle is damaging to the moral lives of children.

In his most recent book, " The Vanishing Face of Gaia ", he rejects scientific modelling that disagrees with the scientific findings that sea levels are rising faster, and Arctic ice is melting faster, than the models predict and he suggests that we may already be beyond the tipping point of terrestrial climate into a permanently hot state.

The process of developing a mathematical model is termed mathematical modelling.

From the point of view of material modelling, masonry is a special material of extreme mechanical properties ( with a very high ratio between strength in compression and in tension ), so that the applied loads do not diffuse as they do in elastic bodies, but tend to percolate along lines of high stiffness, see the figure on the right and watch a video for more details.

For applications where the solution is dependent on some data, the cost must necessarily be a function of the observations, otherwise we would not be modelling anything related to the data.

The resolved data is further processed in the visual cortex where some areas have specialised functions, for instance area V5 is involved in the modelling of motion and V4 in adding colour.

Wireframing is one of the method of geometric modelling system.

The Z notation (), named after Zermelo – Fraenkel set theory, is a formal specification language used for describing and modelling computing systems.

In terms of a database data integrity refers to the process of ensuring that a database remains an accurate reflection of the universe of discourse it is modelling or representing.

This is often conducted via modelling, using an over-abstract ( and sometimes graphical ) model of the actual system.

In sound synthesis, physical modelling synthesis refers to methods in which the waveform of the sound to be generated is computed by using a mathematical model, being a set of equations and algorithms to simulate a physical source of sound, usually a musical instrument.

Instead, the synthesized speech output is created using additive synthesis and an acoustic model ( physical modelling synthesis ).

Simulation is also used with scientific modelling of natural systems or human systems to gain insight into their functioning.

Karplus-Strong string synthesis is a method of physical modelling synthesis that loops a short waveform through a filtered delay line to simulate the sound of a hammered or plucked string or some types of percussion.