materials thermal radiation and noise

... ' 2.83 While random noise has no exact peak-to-peak value, it is approximately to times the standard deviation Table 2-1 lists a computer routine for calculating the mean and standard deviation ... on the mean and standard deviation, two other terms need to be mentioned In some situations, the mean describes what is being measured, while the standard deviation represents noise and other interference ... provides a more accurate Chapter 2- Statistics, Probability and Noise 8 a Changing mean and standard deviation b Changing mean, constant standard deviation 4 Amplitude Amplitude 19 -2 -2 -4 -4 64...

Ngày tải lên: 13/09/2012, 09:49

... Hz to 80 Hz; band is band-pass and covers 80 Hz to kHz; band is high-pass and covers above kHz; and band is also high-pass and covers above kHz At the encoder the gain of each band is adaptively ... contaminating noise, and only the noisy signal is available In such cases the noise cannot be cancelled out, but it may be reduced, in an average sense, using the statistics of the signal and the noise ... speech enhancement and speech recognition Speech is generated by inhaling air into the lungs, and then exhaling it through the vibrating glottis cords and the vocal tract The random, noise- like, air...

Ngày tải lên: 21/01/2014, 07:20

... shape; examples are pink noise, brown noise and autoregressive noise (e) Impulsive noise: consists of short-duration pulses of random amplitude and random duration (f) Transient noise pulses: consists ... White noise: purely random noise that has a flat power spectrum White noise theoretically contains all frequencies in equal intensity (c) Band-limited white noise: a noise with a flat spectrum and ... the signal and the noise processes The models are then used for the decoding of the underlying states of the signal and noise, and for noisy signal recognition and enhancement Noise and Distortion...

Ngày tải lên: 21/01/2014, 07:20

... Autocorrelation and power spectrum of impulsive noise Impulsive noise is a random, binary-state (“on/off”) sequence of impulses of random amplitudes and random time of occurrence In Chapter 12, a random ... stochastic processes for modelling random noise such as white noise, clutters, shot noise and impulsive noise Bibliography ANDERSON O.D (1976) Time Series Analysis and Forecasting The Box– Jenkins ... Model for Clutters and Impulsive Noise An impulsive noise process consists of a sequence of short-duration pulses of random amplitude and random time of occurrence whose shape and duration depends...

Ngày tải lên: 21/01/2014, 07:20

... µx and covariance matrix Σxx, and that the noise n(m) is also Gaussian with mean vector µn and covariance matrix Σnn The signal and noise pdfs model the prior spaces of the signal and the noise ... with a random input e, output x, and parameter vector θ, is a predictive model of the signal x, and n is an additive random noise process In Figure 4.1, the distributions of the random noise n, ... is the random input of the AR model and n is the random noise Using Equation (4.3), the signal restoration process involves the estimation of both the model parameter vector θ and the random input...

Ngày tải lên: 21/01/2014, 07:20

... Speech Wiener filter Noise states Noise Noise HMMs Figure 5.12 Outline configuration of HMM-based noisy speech recognition and enhancement 5.6 Signal and Noise Model Combination and Decomposition ... Wiener filtering and the spectral subtraction methods described in Chapters and 11) or by combining the noise and the signal models to model the noisy Signal and Noise Model Combination and Decomposition ... signal and the noise HMMs maybe expressed as   MAP s signal = arg max  max f Y (Y , ssignal , s noise M ,η )  s signal  s noise (5.46)   MAP s noise = arg max  max f Y (Y , ssignal , s noise...

Ngày tải lên: 21/01/2014, 07:20

... x(m) and the noise n(m): Ryy = Rxx + Rnn (6.46) rxy = rxx (6.47) and we can also write where Ryy, Rxx and Rnn are the autocorrelation matrices of the noisy signal, the noise- free signal and the noise ... separability: (a) The signal and noise spectra not overlap, and the signal can be recovered by a low-pass filter; (b) the signal and noise spectra overlap, and the noise can be reduced but not ... Filter for Additive Noise Reduction Consider a signal x(m) observed in a broadband additive noise n(m)., and model as y(m) = x(m) + n(m) (6.45) Assuming that the signal and the noise are uncorrelated,...

Ngày tải lên: 21/01/2014, 07:20

... m | m − 1) ~ ( m| m − 1)] = x (7.20) and we have also used the assumption that the signal and the noise are uncorrelated Substitution of Equations (7.9) and (7.16) in Equation (7.15) yields the ... y(m)= x(m) + n(m) (7.34) 2 Let σ e (m) and σ n (m) denote the variances of the excitation signal e(m) and the noise n(m) respectively Substituting Φ(m+1,m)=a(m) and H(m)=1 in the Kalman filter equations ... Recursive estimation of a constant signal observed in noise Consider the estimation of a constant signal observed in a random noise The state and observation equations for this problem are given...

Ngày tải lên: 21/01/2014, 07:20

... X Ba ) 2     (8.55) where X and x are the signal matrix and vector defined by Equations (8.12) and (8.13), and similarly XB and xB are the signal matrix and vector for the backward predictor ... flexibility and better performance Sub-Band Linear Prediction Model 253 In sub-band linear prediction, the signal x(m) is passed through a bank of N band-pass filters, and is split into N sub-band signals ... of a sub-band linear prediction model Linear Prediction Models 254 where Bk and fk0 are the bandwidth and the centre frequency of the kth subband respectively To ensure that each sub-band LP parameters...

Ngày tải lên: 21/01/2014, 07:20

... Hz to 80 Hz; band is band-pass and covers 80 Hz to kHz; band is high-pass and covers above kHz; and band is also high-pass and covers above kHz At the encoder the gain of each band is adaptively ... 2.2 White Noise 2.3 Coloured Noise 2.4 Impulsive Noise 2.5 Transient Noise Pulses N 2.6 2.7 2.8 2.9 2.10 Thermal Noise Shot Noise Electromagnetic Noise Channel Distortions Modelling Noise oise ... background noise, thermal noise, electromagnetic radio-frequency noise, co-channel interference, radio-channel distortion, echo and processing noise Noise can cause transmission errors and may even...

Ngày tải lên: 25/01/2014, 13:20

... Coloured Noise 33 2.4 Impulsive Noise .34 2.5 Transient Noise Pulses 35 2.6 Thermal Noise 36 viii Contents 2.7 Shot Noise 38 2.8 Electromagnetic Noise ... noise, including thermal noise, shot noise, acoustic noise, electromagnetic noise and channel distortions, are considered The chapter concludes with an introduction to the modelling of noise processes ... detection and removal of impulsive noise and transient noise pulses In Chapter 12, impulsive noise is modelled as a binary−state non-stationary process and several stochastic models for impulsive noise...

Ngày tải lên: 25/01/2014, 13:20

... {vP+1, , vN} span the noise subspace and have σ n as their eigenvalues Since the signal and noise eigenvectors are orthogonal, it follows that the signal subspace and the noise subspace are orthogonal ... of the noisy signal into a signal subspace and a noise subspace The orthogonality of the signal and noise subspaces is used to estimate the signal and noise parameters In the next chapter, we use ... autocorrelation matrices of the signal x and the noise as R yy = R xx + Rnn = SPS H + σ I n (9.93) where Rxx=SPSH and Rnn=σn2I are the autocorrelation matrices of the signal and noise processes, the exponent...

Ngày tải lên: 26/01/2014, 07:20

... case of a band-limited random signal if the sampling rate is greater than M times the Nyquist rate However, in many practical cases, the signal is a realisation of a random process, and the sampling ... recognition and decision making systems We started this chapter with a study of the ideal interpolation of a band-limited signal, and its applications in digital-to-analog conversion and in multirate ... original base-band spectrum X(f) and the repetitions or images of X(f) spaced uniformly at frequency intervals of Fs=1/Ts When the sampling frequency is above the Nyquist rate, the baseband spectrum...

Ngày tải lên: 26/01/2014, 07:20

... effect of noise on a signal in the time and the frequency domains 335 Spectral Subtraction where y(m), x(m) and n(m) are the signal, the additive noise and the noisy signal respectively, and m is ... f ) |b and | N ( f ) |b is the time-averaged noise spectra It is assumed that the noise is a wide-sense stationary random process For magnitude spectral subtraction, the exponent b=1, and for ... sounding noise, known as “musical tone noise due to their narrowband spectrum and the tin-like sound The success of spectral subtraction depends on the ability of the algorithm to reduce the noise...

Ngày tải lên: 26/01/2014, 07:20

... 359 Impulsive Noise 12.1.1 Autocorrelation and Power Spectrum of Impulsive Noise Impulsive noise is a non-stationary, binary-state sequence of impulses with random amplitudes and random positions ... binary-state sequence, and expressed as ni (m) = n(m) b(m) (12.6) where b(m) is a binary-state random sequence of ones and zeros, and n(m) is a random noise process Assuming that impulsive noise is an uncorrelated ... the noise from the signal, and the representation domain must be the one that emphasises the distinguishing features of the signal and the noise Impulsive noise is normally more distinct and...

Ngày tải lên: 26/01/2014, 07:20

... of the input and the noise pulse template, and a time delay that can be used to align the input noise and the noise template This information can be used for subtraction of the noise pulse from ... absence of a noise pulse, and provides additional information on the timing and the underlying the states of the noise pulse 13.4.1 Adaptive Subtraction of Noise Pulses The transient noise removal ... distinct states for a transient noise pulse process: (a) the periods during which there are no noise pulses; (b) the initial, and often short and sharp, pulse of a transient noise; (c) the decaying oscillatory...

Ngày tải lên: 26/01/2014, 07:20

... convergence The sub-bandbased system is shown in Figure 14.11 The sub-band analyser splits the input signal into N sub-bands Assuming that the sub-bands have equal bandwidth, each sub-band occupies only ... using an adaptive FIR filter and incorporation a echo/speech classifier For those time instants when speaker A is talking, and speaker B is listening and silent, and only echo is present from ... , xA(m–P)] and w(m)=[w0(m), , wP–1(m)] are the input signal vector and the coefficient vector of the echo canceller, and e(m) is the difference between the signal on the echo line and the output...

Ngày tải lên: 26/01/2014, 07:20

... Y(f), X(f), H(f) and N(f) are the frequency spectra of the channel output, the channel input, the channel response and the additive noise respectively Ignoring the noise term and taking the logarithm ... large, and this can lead to noise amplification if the signal-to -noise ratio is low 15.1.2 Equalization Error, Convolutional Noise The equalization error signal, also called the convolutional noise, ... non-linearities, and to estimate a non-Gaussian signal in a high level of Gaussian noise 454 Equalization and Deconvolution 15.6.1 Higher-Order Moments, Cumulants and Spectra The kth order moment of a random...

Ngày tải lên: 26/01/2014, 07:20

... sandpaper The chief types of abrasive sand include sandblast sand, glass-grinding sand, and stone-cutting sand Sand for stone sawing and for marble and glass grinding is usually ungraded, with no ... ABRASIVE SAND Any sand used for abrasive and grinding purposes, but the term does not include the sharp grains obtained by crushing quartz and used for sandpaper The chief types of abrasive sand include ... surfacing and finishing metals, stone, wood, glass, and other materials by abrasive action The natural abrasives include the diamond, emery, corundum, sand, crushed garnet and quartz, tripoli, and...

Ngày tải lên: 13/02/2014, 09:20