Random Data

Bendat, Julius S.; Piersol, Allan G.

doi:10.1002/9781118032428

Cited by 1,241 publications

(388 citation statements)

References 0 publications

Supporting

Mentioning

327

Contrasting

Unclassified

Order By: Relevance

“…Bendat and Piersol (1986) have shown that the expectation values of the cross-correlation function will show a peak around the mean transit time t 0 for nondispersive advection. The actually calculated cross-correlation, as a stochastic estimator, will also contain statistic uncertainties, including an uncertainty in the actual value of t 0 .…”

Section: Inter-annual To Multi-decadal Changes Of Lsw In the Irmingermentioning

confidence: 99%

Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

Aken

Jong

Yashayaev

2011

Deep Sea Research Part I: Oceanographic Research Papers

View full text Add to dashboard Cite

a b s t r a c tTime series of profiles of potential temperature, salinity, dissolved oxygen, and planetary potential vorticity at intermediate depths in the Labrador Sea, the Irminger Sea, and the Iceland Basin have been constructed by combining the hydrographic sections crossing the sub-arctic gyre of the North Atlantic Ocean from the coast of Labrador to Europe, occupied nearly annually since 1990, and historic hydrographic data from the preceding years since 1950. The temperature data of the last 60 years mainly reflect a multi-decadal variability, with a characteristic time scale of about 50 years. With the use of a highly simplified heat budget model it was shown that this long-term temperature variability in the Labrador Sea mainly reflects the long-term variation of the net heat flux to the atmosphere. However, the analysis of the data on dissolved oxygen and planetary potential vorticity show that convective ventilation events, during which successive classes of Labrador Sea Water (LSW) are formed, occurring on decadal or shorter time scales. These convective ventilation events have performed the role of vertical mixing in the heat budget model, homogenising the properties of the intermediate layers (e.g. temperature) for significant periods of time. Both the long-term and the near-decadal temperature signals at a pressure of 1500 dbar are connected with successive deep LSW classes, emphasising the leading role of Labrador Sea convection in running the variability of the intermediate depth layers of the North Atlantic. These signals are advected to the neighbouring Irminger Sea and Iceland Basin. Advection time scales, estimated from the 60 year time series, are slightly shorter or of the same order as most earlier estimates, which were mainly based on the feature tracking of the spreading of the LSW 94 class formed in the period 1989

show abstract

Section: Inter-annual To Multi-decadal Changes Of Lsw In the Irmingermentioning

confidence: 99%

Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

Aken

Jong

Yashayaev

2011

Deep Sea Research Part I: Oceanographic Research Papers

View full text Add to dashboard Cite

show abstract

“…To be strictly stationary, all moments of the data must be shown to be constant [23]. To reject the assumption of stationarity, it is sufficient to show that the joint probability density function, f(x,y), varies appreciably over the interval.…”

Section: A Measure Of Stationaritymentioning

confidence: 99%

“…Analyses which require stationarity may still be performed with some degree of confidence if the data can be shown to be weakly stationary. Bendat and Piersol [23] suggest a test for weak stationarity in which a set of statistics are taken from the data for several subintervals, as was done for the joint density function, above. The set are then tested for trends using a 'reverse arrangements' hypothesis test in which the number of transitions from 'less than' to 'greater than' are counted in the data.…”

Section: A Measure Of Stationaritymentioning

confidence: 99%

Determining correlation and coherence lengths in turbulent boundary layer flight data

Palumbo

2012

Journal of Sound and Vibration

View full text Add to dashboard Cite

a b s t r a c tWall pressure data acquired during flight tests at several flight conditions are analysed and the correlation and coherence lengths of the data reported. It is found that the correlation and coherence lengths are influenced by the origin of the structure producing the pressure and the frequency bandwidth over which the analyses are performed. It is shown how the frequency bandwidth biases the correlation length and how the convection of the pressure field might reduce the coherence measured between sensors. A convected form of the cross correlation and cross spectrum is introduced to compensate for the effects of convection. Coherence lengths measured in the streamwise direction appear much longer than expected. Coherent structures detected using the convected cross correlation do not exhibit an exponential coherent power decay.Published by Elsevier Ltd.

show abstract

“…5(b) shows the normalized probability distribution functions for τ = 0.1 s using 8 × 10 5 samples. The shape of the PDFs correspond to a Gaussian distribution, as expected for large sample sizes according to the Central Limit Theorem (Bendat & Piersol 1986). Such a normal distribution can clearly be distinguished from other kinds of distribution functions (e.g.…”

Section: T H E T R a N S I T I O N O F T H E S C A L I N G B E H Av Imentioning

confidence: 55%

Statistical properties of the seismic noise field: influence of soil heterogeneities

Pilz¹,

Parolai²

2014

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YSeismic noise is generally considered as a reproducible and temporarily stationary natural source of energy. We present a study on the statistical features of the soil motion due to the seismic noise wavefield and the dependencies on the near-surface geology. We have investigated the variations of the 3-D average squared soil displacement over different timescales. The results clearly indicate ballistic behaviour for short timescales being indicative for the properties of the shallow material. Differences in the structural heterogeneity of the subsoil produce different scattering properties, changing the character of motion from nearly ballistic to diffusive on frequency-dependent timescales for all materials. Although in a strict sense the seismic noise wavefield is not completely isotropic, an ultimate pre-condition for a diffusive wavefield, the deviations compared to a uniform distribution are rather small. This means that the emergence of the Green's function is effective for all network sites after a sufficient self-averaging process that is provided by the scattering and the random spatial-temporal noise source distribution.

show abstract

Random Data

Cited by 1,241 publications

References 0 publications

Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

Determining correlation and coherence lengths in turbulent boundary layer flight data

Statistical properties of the seismic noise field: influence of soil heterogeneities

Contact Info

Product

Resources

About