The problem of discrimination between two stationary AR (p) plus noise processes is considered when the noise process are different in two models. The discrimination rule leads to a quadratic form with cumbersome matrices. An approximate and analytic form is given to distribution of the discriminant. The simulation study has been used to show the performance of discrimination rule. The cumulants of discriminant function are obtained and show them to be very close to the true values given in literature.

The analysis of GEOCHEMICAL data in frequency domain, as indicated in this research study, can provide new exploratory information that may not be exposed in spatial domain. To identify deep GEOCHEMICAL anomalies, sulfide zone and GEOCHEMICAL NOISES in Dalli Cu– Au porphyry deposit, a new approach based on coupling Fourier transform (FT) and principal component analysis (PCA) has been used. The relationship between frequency attributes of surface GEOCHEMICAL data and mineralizing depth has been discussed. To determine the exploratory features in different frequencies, high- and low-pass filters have been performed on frequency domain; PCA method has been employed on these frequency bands separately. The results of this study have identified the mineralizing elements and showed the relationship between high- and low-frequencies and depths of anomalies. The GEOCHEMICAL halos of mineral deposits at different depths affected frequency distribution of elements in the surface. The information obtained from geophysical studies and exploration drillings, such as, trenches and boreholes, confirm the results of FT–PCA method. This new approach is very effective tool to identify the promising anomalies and deep mineralization without drilling.

Random or incoherent noise is an important type of seismic noise, which can seriously affect the quality of the data. Therefore, decreasing the level of this category of NOISES is necessary for increasing the signal-to-noise ratio (SNR) of seismic records. Random NOISES and other events overlap each other in time domain, which makes it difficult to attenuate them from seismic records. In this research, a new technique is produced, by joining FX deconvolution (FXD) and a special kind of median filter in order to suppress random noise from seismic records. The technique is operated in some stages; firstly, FXD is tried to eliminate the Gaussian noise, and the median filter is fixed to diminish the spike-like noise. The synthetic dataset and field data examples (from an oil field in the southwest of Iran) have been employed to demonstrate that random noise reduction can be attained, while the signal content will not be destroyed considerably. The final results indicate the authority of the proposed strategy in suppressing random NOISES, whereas signal information is almost protected during the filtering.

The present study was an attempt to empirically find out if the very presence of background noise would impair L2 listening comprehension, and also to explore to what extent the nature of noise would mediate this disruption. Regarding the latter point, the effect of lexicality, meaning, and Ll/L2 dichotomy were investigated. The participants listened, within a repeated-measures design, to ten L2 passages two of which were against a quiet background and others were in the presence of either radio static (roughly representing the white noise, Le., the standard non-lexical noise), Russian (as a totally unknown language) noise, English (L2) noise, or Persian (Ll) noise. Matched t-test results showed the background noise to be substantially disruptive of L2 listening comprehension. In addition, more masking was found from white noise that from competing speech, including the lexicality reduced the amount of masking. The effect of meaning, too, did not reach significance: Meaningless background interfered with L2 listening comprehension as much as did meaningful speech. Similarly, Ll and L2~oises were statistically equal in their power to corrupt L2 listening performance.

The stochastic models for ship heave motion in irregular sea waves based on white and colored NOISES are examined. For this purpose the deterministic model transfers to stochastic models by adding different noise terms in force and then these models are solved analytically and numerically. Finally an investigation is undertaken to examine the parameter estimation problem of second order stochastic differential equations when some of the measurements are unavailable or missing data. Several simulation results are presented to illustrate the performance of the estimators.

The uncertainty on the values of the measured residual stresses in hole-drilling integral method, the most widely used technique for measuring residual stress, will be called hereinafter as residual stress NOISES, which initiate high sensitivity of stress to strain measurement errors due to illconditioning of inverse integral equations. This study aimed to investigate the use of Chebyshev points to decrease residual stress NOISES in the hole drilling method. The Chebyshev points were extended to hole-drilling increments from surface to specified interior depth. The bending of an aluminum beam was used to validate the extended method, and the results were compared with the standard reduction NOISES technique, Tikhonov-Morozov, and optimum steps technique. The result obtained from the extended method was shown to lead not only an accurate determination of de-noised residual stress, but also a simple calculation procedure in comparison with the Tikhonov-Morozov and optimal steps method. The results indicate that the use of modified Chebyshev points decreased the mean absolute error of residual stress to 8. 17 MPa from 14 MPa in Tikhonov-Morozov and 10. 52 MPa in optimum steps methods.

Along with exhaust emissions and Fuel Consumptions (FCs), noise emission from cars is one of the main concerns of automotive industry. Hybridization is a promising method to not only make automobiles more environmentally-friendly, but also reduce their noise emissions. However, a proper control design for Hybrid Electric Vehicles (HEVs) to make noise emissions lower is still required in addition to exhaust emissions and FC reductions. In this study, we modify Equivalent Consumption Minimization Strategy (ECMS) to keep the engine noise less than tire/road noise during driving. A test bench is established for calculating the engine noise and brake specific FC. Moreover, tire/road noise is experimentally defined as a function of the vehicle speed. It is shown that by implementing the basic ECMS, the engine noise exceeds the tire/road noise in some moments of driving cycle, which is annoying to the passengers. Therefore, a modified ECMS is proposed to limit the candidate engine operating points such that the engine noise does not exceed the tire/road noise. It is shown that the engine noise level is kept below the tire/road noise level by using the modified ECMS at the expense of a very small increase (about 1%) in the vehicle's FC.

Two-phase flow systems analysis data are rear and cause major problems as efficient prediction in operation and control of the system or delay in identifying system parameters behavior. Analysis of the pressure waves through transient conditions can be an effective method to achieve precise results. In the present article, the bubble formation was studied using computational fluid dynamics (CFD) and the acoustic finite element method (FEM). The simulation conducted to obtain the aerodynamic NOISES generated by initiation and separation of bubbles in a vertical column. A Transient three-dimensional model is developed based on VOF method for tracking interface of two phases and large eddy simulation (LES) for an accurate calculation of pressure fluctuations. The model is simulated with the aid of the commercial software ANSYS FLUENT based on the finite volume method. To obtain convergence the implicit body force treatment is taken into account PISO algorithm is used to calculate a consistent result between velocity and pressure field. Pressure is discretized with PRESTO scheme. The RANS solution is used to calculate the initial flow field. In this case momentum is discretized with the second order upwind scheme and the geometric reconstruction scheme has been used as the volume fraction discretization scheme. Due to the importance of interface tracking in sound sources recognition and the problems which occur during adding LES model in the simulation, different interface reconstruction methods has been compared. High Resolution Interface Capturing scheme (HRIC) is selected as the best method. The Fofwcs Williams and Hawking (FWH) equation is used as an extension of the classical Lighthill aerodynamic acoustics for predicting far field NOISES. Sound sources are extracted by taking samples of pressure fluctuations from Wall penetration and virtual plane that is defined parallel to flow. These sources are investigated in the moment of separation and formation of bubble. In this paper are concluded that the largest fluctuation occur during necking of bubbles, while the smallest bubble produced the biggest peak in acoustic fluctuation curves. Besides time analysis, the pressure fluctuation is transferred from time domain to frequency by Fourier transform method and spectral analysis is performed on the data. The spectral analysis are compared to experimental results to better understand the effects of turbulence models, flow rate and methods of taking sample on the acoustic frequency response. The spectra of the filtered acoustic data (at airflow rate of 240 lit/min) shows a peak at about 40 Hz and is shown frequency response increases by the decrement of flow rate in bubbly flow. In this research frequency merge of two bubbles is demonstrated at 800 Hz and frequency response is used to estimate the bubble size.