Relationship between Wave Height and Sampling Interval: Revisiting Individual Wave Analysis Method

2018 ◽  
Vol 85 ◽  
pp. 1136-1140
Author(s):  
Hong-Yeon Cho ◽  
Hyuk-Jin Choi ◽  
Shin-Taek Jeong ◽  
Dong-Hui Ko
Keyword(s):  
Wave Height ◽  
Sampling Interval ◽  
Analysis Method ◽  
Wave Analysis ◽  
Individual Wave

scholarly journals REDUCTION OF WAVE OVERTOPPING RATE BY THE USE OF ARTIFICIAL REEFS

1988 ◽  
Vol 1 (21) ◽  
pp. 23
Author(s):  
Toru Sawaragi ◽  
Ichiro Deguchi ◽  
San-Kil Park
Keyword(s):  
Wave Breaking ◽  
Artificial Reef ◽  
Numerical Procedure ◽  
Artificial Reefs ◽  
Irregular Waves ◽  
Analysis Method ◽  
Wave Analysis ◽  
Wave Overtopping ◽  
Unidirectional Flow ◽  
Individual Wave

A wave overtopping rate from a sea dike of various toe depths is formulated based on a weir model in an unidirectional flow. To evaluated the wave overtopping rate from a seadike on an artificial reef by the weir model, a numerical procedure for predicting wave transformations including the effect of forced wave breaking on the reef is constructed. After confirming the applicability of the model through experiments with regular and irregular waves, the effect of artificial reef on wave overtopping is discussed. So-called individual wave analysis method is shown to he applicable to the wave overtopping caused by irregular waves.

scholarly journals ON JOINT DISTRIBUTION OF WAVE HEIGHTS AND DIRECTIONS

1988 ◽  
Vol 1 (21) ◽  
pp. 37 ◽  
Author(s):  
Masahiko Isobe
Keyword(s):  
Wave Height ◽  
Joint Distribution ◽  
Joint Probability ◽  
Irregular Waves ◽  
Wave Analysis ◽  
Wave Direction ◽  
Individual Wave ◽  
Wave Heights ◽  
The Individual ◽  
Joint Probability Density

In the individual wave analysis of short-crested irregular waves, the wave direction of an individual wave is an important quantity as well as the wave height and period. In this paper, the joint probability density of the wave height and direction is derived theoretically on the assumption of a narrow-banded frequency spectrum. A field experiment was carried out to examine the validity of the theory. The measured joint distribution agreed well with that predicted by the theory.

scholarly journals Optical Design of Porous ZnO/TiO2 Films for Highly Transparent Glasses with Broadband Ultraviolet Protection

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Han Sung Song ◽  
Young Jin Yoo ◽  
Gil Ju Lee ◽  
Ki Soo Chang ◽  
Young Min Song
Keyword(s):  
Optical Design ◽  
Volume Averaging ◽  
Film Structure ◽  
Visible Range ◽  
Analysis Method ◽  
Wave Analysis ◽  
Electrical Field ◽  
Rigorous Coupled Wave Analysis ◽  
Ultraviolet Protection ◽  
Rigorous Coupled Wave

We present a design of a bilayer porous film structure on a glass substrate for the highly efficient ultraviolet (UV) protection with high visible-light transparency. To effectively block UVB (280–315 nm) and UVA (315–400 nm), titanium dioxide (TiO2) and zinc oxide (ZnO) are used as absorbing layers having the appropriate coverages in different UV ranges with extinction coefficients, respectively. We show the process of refractive index (RI) matching by controlling porosity (Pr). Effective RIs of porous media with TiO2 and ZnO were calculated based on volume averaging theory. Transmittances of the designed films with different effective RIs were calculated using rigorous coupled-wave analysis method. Using admittance loci method, the film thickness was optimized in center wavelengths from 450 to 550 nm. The results show that the optimal design provides high UV shielding performance at both UVA and UVB with high transparency in the visible range. We also analyze electrical field distributions in each layer and angle dependency with 3D HSV color map.

scholarly journals SAMPLING BIAS IN THE ESTIMATION OF SIGNIFICANT WAVE HEIGHT EXTREME VALUES

2017 ◽  
pp. 33
Author(s):  
Fabio Dentale ◽  
Ferdinando Reale ◽  
Felice D'Alessandro ◽  
Leonardo Damiani ◽  
Angela Di Leo ◽  
...  
Keyword(s):  
Wave Height ◽  
Time Resolution ◽  
Significant Wave Height ◽  
Extreme Values ◽  
Sampling Bias ◽  
Threshold Value ◽  
Return Time ◽  
Sampling Interval ◽  
Significant Wave ◽  
Wave Models

It has been shown before, and it is intuitively evident, that in a Significant Wave Height (SWH) time series, the longer the sampling interval, the lower is the number of events which are above a given threshold value. As a consequence, the use of data with a low time resolution (such as a 3 h sampling, for instance) causes a considerable undervaluation of the extreme SWH values for a given return time RT. In this paper an example of such a bias is provided, and a method is suggested to estimate it on a regional basis. Results may help to improve the use of historical wave meters data which were often collected with a low time resolution, and may also provide a tool to improve the application of Numerical Meteo-Wave models to the evaluation of extremes.

Hydrodynamic Study on Added Resistance Using Unsteady Wave Analysis

2013 ◽  
Vol 57 (04) ◽  
pp. 220-240
Author(s):  
Masashi Kashiwagi
Keyword(s):  
Direct Measurement ◽  
Incident Wave ◽  
Ship Motions ◽  
Analysis Method ◽  
Added Resistance ◽  
Wave Analysis ◽  
Linear Superposition ◽  
The Fourier Transform ◽  
Wave Induced ◽  
Incident Waves

It is known that the added resistance in waves can be computed from ship-generated unsteady waves through the unsteady wave analysis method. To investigate the effects of nonlinear ship-generated unsteady waves and bluntness of the ship geometry on the added resistance, measurements of unsteady waves, wave-induced ship motions, and added resistance were carried out using two different (blunt and slender) modified Wigley models. The ship-generated unsteady waves are also produced by the linear superposition using the waves measured for the diffraction and radiation problems and the complex amplitudes of ship motions measured for the motion-free problem in waves. Then a comparison is made among the values of the added resistance by the direct measurement using a dynamometer and by the wave analysis method using the Fourier transform of measured and superposed waves. It is found that near the peak of the added resistance where ship motions become large, the degree of nonlinearity in the unsteady wave becomes prominent, especially at the forefront part of the wave. Thus, the added resistance evaluated with measured waves at larger amplitudes of incident wave becomes much smaller than the values by the direct measurement and by the wave analysis with superposed waves or measured waves at smaller amplitude of incident wave. Discussion is also made on the characteristics of the added resistance in the range of short incident waves.

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