scholarly journals The problem of determining the threshold for statistical analysis by the POT method: Application to wave data on the Moroccan Atlantic coast

2021 ◽  
Vol 314 ◽  
pp. 04002
Author(s):  
Hosny Bakali ◽  
Ismail Aouiche ◽  
Najat Serhir
Keyword(s):  
Wave Height ◽  
Atlantic Coast ◽  
Sensitivity Study ◽  
Exponential Model ◽  
Wave Data ◽  
Design Wave Height ◽  
Peak Over Threshold ◽  
Threshold Variation ◽  
Data Censoring

In a study of extreme waves by the Peak Over Threshold (POT) method, the determination of the threshold of data censoring is an essential step. A wrong choice of the threshold can lead to erroneous results of the wave height design and consequently a bad design of maritime structures such as breakwaters for deep sea ports. In this study, we analyzed the influence of the threshold variation on the results of the hundred-year return period waves, generally considered for the design of maritime structures. The sensitivity study allowed us to confirm that the exponential model is the best probability distribution to describe wave data in two points on the Moroccan Atlantic coast for the wave data period from 1958 to 2019. This study also confirmed that a wrong choice of the statistical distribution and a wrong choice of the threshold lead to significant errors in the estimation of design wave height.

scholarly journals Wave transformation around breakwater (case study: tourism harbour, Eastern Bali, Indonesia)

2021 ◽  
Vol 894 (1) ◽  
pp. 012028
Author(s):  
M N Arsyad ◽  
O Setyandito ◽  
L M Kesuma ◽  
H D Armono ◽  
M Anda ◽  
...  
Keyword(s):  
Wave Height ◽  
Wave Transformation ◽  
Wave Condition ◽  
The Past ◽  
Design Wave Height ◽  
Coastal Modeling ◽  
Before And After ◽  
Modeling Software

Abstract An essential aspect in the sustainable design of breakwater is the determination of the design wave condition. It is predicted by utilizing severe wave conditions of the past 10 to 20 years. The tourism harbor at eastern Bali, Indonesia, is located where extreme wave condition occurs. Therefore, this research studies the wave height before and after constructing a breakwater in the harbor area. The wave height was simulated using numerical modeling. The methodology was performed by using the coastal modeling software of the SMS-CGWAVE model. The result shows the highest design wave height value of 3.9 m in the direction from the southeast. The design breakwater can reduce wave height up to 0.9 m or a 75.5% reduction. Further study is needed to simulate the extension of breakwater length to meet the criterion design of wave height in the harbor basin.

scholarly journals ENGINEERING APPROACH TO NONLINEAR WAVE SHOALING

1982 ◽  
Vol 1 (18) ◽  
pp. 34
Author(s):  
James Walker ◽  
John Headland
Keyword(s):  
Nonlinear Wave ◽  
Wave Height ◽  
Breaking Wave ◽  
Relative Depth ◽  
Laboratory Studies ◽  
Design Wave Height ◽  
Point Of Interest ◽  
Wave Shoaling ◽  
Sloping Bottom

Determination of a design wave height at a coastal structure requires calculation of a shoaling coefficient or determination of the maximum probable breaking wave height at the point of interest. In shallow water over a sloping bottom, low steepness waves are not accurately predicted by linear shoaling coefficients. Empirical breaking indices are inconsistent with both linear and nonlinear wave theories. Nevertheless, the coastal engineer must select a design wave in order to responsibly design the structure. A graphical procedure is presented herein to relate the equivalent deepwater wave to a breaking wave as it transitions into shoaling water. The procedure provides the coastal engineer with a more consistent understanding of the shoaling process. The results furthermore identify regions of relative depth and steepness where discrepancies arise when using linear shoaling coefficients that may significantly alter engineering design and laboratory studies.

Weather Window Analysis of Irish and Portuguese Wave Data With Relevance to Operations and Maintenance of Marine Renewables

2013 ◽  
Author(s):  
Michael O’Connor ◽  
Tony Lewis ◽  
Gordon Dalton
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
West Coast ◽  
Atlantic Coast ◽  
The West ◽  
Wave Data ◽  
Window Analysis ◽  
Operations And Maintenance ◽  
Wave Heights ◽  
Waiting Periods

This paper presents the results of a weather window analysis of wave data from the west coast of Ireland and the Atlantic coast of Portugal in order to quantify the levels of access to ocean energy renewables, which may be deployed there, for operation and maintenance activities. In order to operate and maintain offshore marine renewables, a device will have to be accessible for a certain period of time. This will require a weather window consisting of a consecutive period of wave heights low enough and long enough for the device to be accessed. It is important to quantify what the levels of access are off the Irish west coast and Portuguese Atlantic coast given their high wind and wave resource. Wave data from two wave buoys, the M3 buoy located 56km off the west coast of Ireland and the Leixoes buoy located 19km off the Portuguese coast, are analysed to quantify the levels of access that exist. The data is used to quantify the general regimes at both sites by presenting the wave energy resource, the mean annual exceedance and the wave height frequency at both sites. The levels of access are quantified at operations and maintenance (O/M) access limits of Hs 1.0, 1.5, 2.0 and 2.5m wave height, by presenting the number of windows and the percentage of the year that these windows make up as well as the total number of hours, monthly and annual, that the wave heights are below these limits. Also presented are the waiting periods between windows by showing both the longest individual waiting periods between windows in a year and also the total intervals between windows in a year. The levels of access observed off Ireland and Portugal are then compared to levels of access observed at other marine renewable locations, namely the North Sea, Irish East Coast and Pacific North-western US coast. The results indicate that the levels of access off Ireland and Portugal are far below those observed at other marine renewable locations, and at the lower wave height access limits, there are very few suitable weather windows and considerable winter waiting periods between these windows. The implications of these low levels of access suggest that maintaining wave energy converters, off the west coast, may not be feasible and devices will need to be brought ashore for O/M activities.

Estimation of design wave height using empirical simulation technique

2013 ◽  
Vol 61 ◽  
pp. 39-49 ◽  
Author(s):  
Kyung-Duck Suh ◽  
Munki Kim ◽  
Jeho Chun
Keyword(s):  
Wave Height ◽  
Simulation Technique ◽  
Design Wave Height

scholarly journals Junction Parameter Extraction for Electronic Device Characterization

2004 ◽  
Vol 27 (2) ◽  
pp. 61-67
Author(s):  
S. Dib ◽  
C. Salame ◽  
N. Toufik ◽  
A. Khoury ◽  
F. Pélanchon ◽  
...  
Keyword(s):  
Electronic Device ◽  
Control Process ◽  
Parameter Extraction ◽  
Exponential Model ◽  
Voltage Characteristic ◽  
Model Parameters ◽  
Current Voltage Characteristic ◽  
Device Characterization ◽  
Current Voltage

A new method for the extraction of junction parameters from a description of the current–voltage characteristic is developed. A simulation is performed and a high accuracy is obtained for the determination of the singleexponential model parameters. The method is easy to implement in a control process for device characterization. An application, achieved to observe the degradation of the emitter–base junction of a bipolar transistor during an aging experiment, shows that the evolutions of the single exponential model parameters versus time introduce a means for degradation quantification.

scholarly journals A New Method for the Extraction of Diode Parameters Using a Single Exponential Model

2000 ◽  
Vol 22 (3) ◽  
pp. 157-163 ◽  
Author(s):  
S. Dib ◽  
M. De La Bardonnie ◽  
A. Khoury ◽  
F. Pelanchon ◽  
P. Mialhe
Keyword(s):  
Least Squares Method ◽  
Exponential Model ◽  
New Method ◽  
Ordinate Axis ◽  
Straight Line ◽  
Current Voltage ◽  
Method Approach ◽  
Single Exponential

A new method for extracting junction parameters of the single diode model is presented. A least squares method approach considers the deviation ∆V=f(I) between the experimental current-voltage (I-V) characteristic and a theoretical arbitrary characteristic. A specific case- the ∆V graph reducing to a straight line–is identified and the knowledge of the slope and of the intercept with the ordinate axis leads to the determination of the junction parameters. The method is applied to the characterization of the emitter-base junction of transistors and the results are discussed.

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