3. Measurement and prediction

2019 ◽  
pp. 34-49
Author(s):  
David George Bowers ◽  
Emyr Martyn Roberts
Keyword(s):  
Harmonic Analysis ◽  
Standard Method ◽  
Curve Fitting ◽  
Great Accuracy ◽  
Horizontal Flow ◽  
Physical Oceanography ◽  
Success Story ◽  
Fitting Procedure ◽  
Tidal Data ◽  
Tidal Streams

‘Measurement and prediction’ outlines the ways in which tides and tidal currents can be measured, and considers the standard method of analysing tidal data using a curve-fitting procedure known as harmonic analysis. Tides, unusually for natural events, can be forecast with great accuracy for years in advance. The ability to do this and make people safer at sea is probably the greatest practical success story of the science of physical oceanography. There are two aspects of the problem to be considered: the rise and fall of the level of the sea, which we shall call the tide; and the horizontal flow of the water, called tidal streams or currents.

Parametric Description of Vibration Using the Autocorrelation Function

2009 ◽  
Vol 147-149 ◽  
pp. 606-611
Author(s):  
Adam Kotowski
Keyword(s):  
Autocorrelation Function ◽  
Curve Fitting ◽  
Vibration Signal ◽  
Analytic Form ◽  
Parametric Representation ◽  
Rotating Machine ◽  
Fitting Procedure ◽  
Power Spectral ◽  
Parametric Description ◽  
Harmonic Components

The paper presents the use of the autocorrelation function for the description of vibrations and the problems connected with. The proposed method is based on the analysis of vibration signal recorded for machine during its operations using an analytic form of the autocorrelation function. The parameters are obtained using a curve fitting procedure. To keep a quality of parametric representation of considered vibration, only the curve fitting causes a determination coefficient over 0.90 is taken into consideration. Therefore, the autocorrelation functions are submitted for the fast Fourier transform to be helped, in determination of number of the dominant harmonic components. Also, the analytic form and parameters of power spectral density has been also calculated. Finally, the set of parameters has been collected to describe the selected fragment of vibration of the simple rotating machine. The influence of duration of analyzed vibration on the parameters values is also examined in this work.

scholarly journals Tidal, wave, current and sediment flow patterns in wet season in the estuary of Porong River Sidoarjo, Indonesia

2018 ◽  
Vol 177 ◽  
pp. 01016
Author(s):  
A. Kisnarti Engki ◽  
Dj. Prasita Viv
Keyword(s):  
Flow Patterns ◽  
Current Data ◽  
Tidal Wave ◽  
Physical Oceanography ◽  
Sediment Thickness ◽  
Wet Season ◽  
The West ◽  
Tidal Current Velocity ◽  
Tidal Data ◽  
Sediment Flow

The objectives of this research are to analyze characteristics of physical oceanography, such as : tides, waves, currents, and discharges at Muara Kali Porong. This research also discuss sediment flow patterns and morphology in around the Estuary of Porong River. Tidal data were used as correction to the depth. The calculation to determine the tidal current velocity and wind data along with current data are used for simulation model. Sedimentation process with a simulation of 15 days in the West Season occured in the Northeast of Lusi Island with sediment thickness ranged from 1.6 to 2.6 m.

Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings

2005 ◽  
Vol 98 (4) ◽  
pp. 1511-1518 ◽  
Author(s):  
Geoffrey A. Head ◽  
Christopher M. Reid ◽  
Elena V. Lukoshkova
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Curve Fitting ◽  
Animal Studies ◽  
Similar Rate ◽  
Rate Of Change ◽  
Logistic Curve ◽  
Fitting Procedure ◽  
Logistic Method

We developed an asymmetric double logistic curve-fitting procedure for circadian analysis that can determine the rate of change in variables during the day-to-night separately from the night-to-day transition for use in animal studies. We now have applied this procedure to 24-h systolic (SAP) and diastolic arterial pressure (DAP) and heart rate ambulatory recordings from 302 patients. In 292 cases, all parameters showed a pattern of higher day and lower night values. In men there was a similar rate of transition between day and night or from night to day for both SAP and DAP that lasted 3–4 h, indicating a symmetrical diurnal pattern. By contrast, women showed a faster rate of decrease in mean arterial pressure in the evening compared with men ( P < 0.05) and therefore showed an asymmetric diurnal SAP pattern. For both men and women, there was a markedly greater rate of morning increase in heart rate compared with the rate of evening decrease (2.2- and 1.9-fold, respectively, P < 0.001). The logistic method provided a better fit than the square-wave or the cosinor method ( P < 0.001) and more appropriately detected nondippers. We conclude that analysis of ambulatory recordings by a new logistic curve-fitting method reveals more rapid reductions in evening SAP in women than men but both have two- to threefold more rapid morning rates of tachycardia. The ability of the double logistic method to determine the diurnal blood pressure rates of change independently is key to determining new markers for cardiovascular risk.

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